1.
Armenian cucumber
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The Armenian cucumber, Cucumis melo var. flexuosus, is a type of long, slender fruit which tastes like a cucumber and looks somewhat like a cucumber inside. It is actually a variety of muskmelon, a closely related to the cucumber. It is also known as the cucumber, snake cucumber, snake melon. It should not be confused with the snake gourds, the skin is very thin, light green, and bumpless. It has no bitterness and the fruit is almost always used without peeling and it is also sometimes called a gutah. The Armenian cucumber grows approximately 30 to 36 inches long and it grows equally well on the ground or on a trellis. Armenian cucumber plants prefer to grow in sun for most of the day. The fruit is most flavorful when it is 12-15 inches long, Pickled Armenian cucumber is sold in Middle Eastern markets as Pickled Wild Cucumber. It is said by Hasselquist to be the “queen of cucumbers, refreshing, sweet, solid, fact sheet from the University of Florida
2.
Taxonomy (biology)
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Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
3.
Plant
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Plants are mainly multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae. The term is generally limited to the green plants, which form an unranked clade Viridiplantae. This includes the plants, conifers and other gymnosperms, ferns, clubmosses, hornworts, liverworts, mosses and the green algae. Green plants have cell walls containing cellulose and obtain most of their energy from sunlight via photosynthesis by primary chloroplasts and their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic and have lost the ability to produce amounts of chlorophyll or to photosynthesize. Plants are characterized by sexual reproduction and alternation of generations, although reproduction is also common. There are about 300–315 thousand species of plants, of which the great majority, green plants provide most of the worlds molecular oxygen and are the basis of most of Earths ecologies, especially on land. Plants that produce grains, fruits and vegetables form humankinds basic foodstuffs, Plants play many roles in culture. They are used as ornaments and, until recently and in variety, they have served as the source of most medicines. The scientific study of plants is known as botany, a branch of biology, Plants are one of the two groups into which all living things were traditionally divided, the other is animals. The division goes back at least as far as Aristotle, who distinguished between plants, which generally do not move, and animals, which often are mobile to catch their food. Much later, when Linnaeus created the basis of the system of scientific classification. Since then, it has become clear that the plant kingdom as originally defined included several unrelated groups, however, these organisms are still often considered plants, particularly in popular contexts. When the name Plantae or plant is applied to a group of organisms or taxon. The evolutionary history of plants is not yet settled. Those which have been called plants are in bold, the way in which the groups of green algae are combined and named varies considerably between authors. Algae comprise several different groups of organisms which produce energy through photosynthesis, most conspicuous among the algae are the seaweeds, multicellular algae that may roughly resemble land plants, but are classified among the brown, red and green algae. Each of these groups also includes various microscopic and single-celled organisms
4.
Flowering plant
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The flowering plants, also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants, with 416 families, approx. 13,164 known genera and a total of c.295,383 known species, etymologically, angiosperm means a plant that produces seeds within an enclosure, in other words, a fruiting plant. The term angiosperm comes from the Greek composite word meaning enclosed seeds, the ancestors of flowering plants diverged from gymnosperms in the Triassic Period, during the range 245 to 202 million years ago, and the first flowering plants are known from 160 mya. They diversified extensively during the Lower Cretaceous, became widespread by 120 mya, angiosperms differ from other seed plants in several ways, described in the table. These distinguishing characteristics taken together have made the angiosperms the most diverse and numerous land plants, the amount and complexity of tissue-formation in flowering plants exceeds that of gymnosperms. The vascular bundles of the stem are arranged such that the xylem and phloem form concentric rings, in the dicotyledons, the bundles in the very young stem are arranged in an open ring, separating a central pith from an outer cortex. In each bundle, separating the xylem and phloem, is a layer of meristem or active formative tissue known as cambium, the soft phloem becomes crushed, but the hard wood persists and forms the bulk of the stem and branches of the woody perennial. Among the monocotyledons, the bundles are more numerous in the stem and are scattered through the ground tissue. They contain no cambium and once formed the stem increases in diameter only in exceptional cases, the characteristic feature of angiosperms is the flower. Flowers show remarkable variation in form and elaboration, and provide the most trustworthy external characteristics for establishing relationships among angiosperm species, the function of the flower is to ensure fertilization of the ovule and development of fruit containing seeds. The floral apparatus may arise terminally on a shoot or from the axil of a leaf, occasionally, as in violets, a flower arises singly in the axil of an ordinary foliage-leaf. There are two kinds of cells produced by flowers. Microspores, which divide to become pollen grains, are the male cells and are borne in the stamens. The female cells called megaspores, which divide to become the egg cell, are contained in the ovule. The flower may consist only of parts, as in willow. Usually, other structures are present and serve to protect the sporophylls, the individual members of these surrounding structures are known as sepals and petals. The outer series is usually green and leaf-like, and functions to protect the rest of the flower, the inner series is, in general, white or brightly colored, and is more delicate in structure. It functions to attract insect or bird pollinators, attraction is effected by color, scent, and nectar, which may be secreted in some part of the flower
5.
Eudicots
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The eudicots, Eudicotidae or eudicotyledons are a monophyletic clade of flowering plants that had been called tricolpates or non-magnoliid dicots by previous authors. The close relationships among flowering plants with tricolpate pollen grains was initially seen in studies of shared derived characters. These plants have a trait in their pollen grains of exhibiting three colpi or grooves paralleling the polar axis. Later molecular evidence confirmed the basis for the evolutionary relationships among flowering plants with tricolpate pollen grains. The term means true dicotyledons, as it contains the majority of plants that have been considered dicots and have characteristics of the dicots, the term eudicots has subsequently been widely adopted in botany to refer to one of the two largest clades of angiosperms, monocots being the other. The remaining angiosperms are sometimes referred to as basal angiosperms or paleodicots, the other name for the eudicots is tricolpates, a name which refers to the grooved structure of the pollen. Members of the group have tricolpate pollen, or forms derived from it and these pollens have three or more pores set in furrows called colpi. In contrast, most of the seed plants produce monosulcate pollen. The name tricolpates is preferred by some botanists to avoid confusion with the dicots, numerous familiar plants are eudicots, including many common food plants, trees, and ornamentals. Most leafy trees of midlatitudes also belong to eudicots, with exceptions being magnolias and tulip trees which belong to magnoliids, and Ginkgo biloba. The name eudicots is used in the APG system, of 1998 and it is applied to a clade, a monophyletic group, which includes most of the dicots. The eudicots can be divided into two groups, the basal eudicots and the core eudicots, basal eudicot is an informal name for a paraphyletic group. The core eudicots are a monophyletic group, a 2010 study suggested the core eudicots can be divided into two clades, Gunnerales and a clade called Pentapetalae, comprising all the remaining core eudicots
6.
Rosids
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The rosids are members of a large clade of flowering plants, containing about 70,000 species, more than a quarter of all angiosperms. The clade is divided into 16 to 20 orders, depending upon circumscription and classification and these orders, in turn, together comprise about 140 families. Fossil rosids are known from the Cretaceous period, molecular clock estimates indicate that the rosids originated in the Aptian or Albian stages of the Cretaceous, between 125 and 99.6 million years ago. The name is based upon the name Rosidae, which had usually been understood to be a subclass, in 1967, Armen Takhtajan showed that the correct basis for the name Rosidae is a description of a group of plants published in 1830 by Friedrich Gottlieb Bartling. The clade was later renamed Rosidae and has been variously delimited by different authors, the name rosids is informal and not assumed to have any particular taxonomic rank like the names authorized by the ICBN. The rosids are monophyletic based upon evidence found by molecular phylogenetic analysis, three different definitions of the rosids were used. Some authors included the orders Saxifragales and Vitales in the rosids, others excluded both of these orders. The circumscription used in this article is that of the APG IV classification, which includes Vitales, the rosids and Saxifragales form the superrosids clade. This is one of three groups compose the Pentapetalae, the others being Dilleniales and the superasterids. The rosids consist of two groups, the order Vitales and the eurosids, the eurosids, in turn, are divided into two groups, fabids and malvids. The rosids consist of 17 orders, in addition to Vitales, there are 8 orders in fabids and 8 orders in malvids. Some of the orders have only recently been recognized and these are Vitales, Zygophyllales, Crossosomatales, Picramniales, and Huerteales. The phylogeny of Rosids shown below is adapted from the Angiosperm Phylogeny Group website, the nitrogen-fixing clade contains a high number of actinorhizal plants. Not all plants in this clade are actinorhizal, however, media related to Rosids at Wikimedia Commons
7.
Cucurbitales
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The Cucurbitales are an order of flowering plants, included in the rosid group of dicotyledons. This order mostly belongs to tropical areas, with limited presence in subtropic, the order includes shrubs and trees, together with many herbs and climbers. One major characteristic of the Cucurbitales is the presence of flowers, mostly pentacyclic. The pollination is performed by insects, but wind pollination is also present. The order consists of roughly 2600 species in eight families, the largest families are Begoniaceae with around 1500 species and Cucurbitaceae with around 900 species. These two families include the economically important plants. Specifically, the Cucurbitaceae include some species, such as squash, pumpkin, watermelon. The Begoniaceae are known for their species, of which there are over 130 with many more varieties. The Cucurbitales are an order of plants with a cosmopolitan distribution, most are herbs, climber herbs, woody lianas or shrubs but some genera include canopy-forming evergreen lauroid trees. Members of the Cucurbitales form an important component of low to tropical forest with greater representation in terms of the number of species. Although not known with certainty the total number of species in the order, conservative estimates indicate about 2600 species worldwide, compared to other flowering plant orders, the taxonomy is poorly understood due to their great diversity, difficulty in identification, and limited study. The order Cucurbitales in the eurosid I clade comprises almost 2600 species in 109 or 110 genera in eight families, tropical and temperate, of different sizes, morphology. It is a case of divergent evolution, in contrast, there is convergent evolution with other groups not related due to ecological or physical drivers toward a similar solution, including analogous structures. Some species are trees that have similar foliage to the true laurels due to convergent evolution, the patterns of speciation in the Cucurbitales are diversified in a high number of species. They have a distribution with centers of diversity in Africa, South America. They most likely originated in West Gondwana 67–107 million years ago, so the oldest split could relate to the break-up of Gondwana in the middle Eocene to late Oligocene, the group reached their current distribution by multiple intercontinental dispersal events. The Cucurbitales comprise the families, Apodanthaceae, Anisophylleaceae, Begoniaceae, Coriariaceae, Corynocarpaceae, Cucurbitaceae, Tetramelaceae, some of the synapomorphies of the order are, leaves in spiral with secondary veins palmated, calyx or perianth valvate, and the elevated stomatal calyx/perianth bearing separate styles. The two whorls are similar in texture, tetrameles nudiflora is a tree of immense proportions of height and width, Tetramelaceae, Anisophylleaceae, and Corynocarpaceae are tall canopy trees in temperate and tropical forests
8.
Cucurbitaceae
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The Cucurbitaceae family ranks among the highest of plant families for number and percentage of species used as human food. The Cucurbitaceae consist of 98 proposed genera with 975 species, mainly in tropical and subtropical. All species are sensitive to frost, most of the plants in this family are annual vines, but some are woody lianas, thorny shrubs, or trees. Many species have large, yellow or white flowers, the stems are hairy and pentangular. Tendrils are present at 90° to the petioles at nodes. Leaves are exstipulate alternate simple palmately lobed or palmately compound, the flowers are unisexual, with male and female flowers on different plants or on the same plant. The female flowers have inferior ovaries, the fruit is often a kind of modified berry called a pepo. One of the oldest fossil records so far is Cucurbitaciphyllum lobatum from the Paleocene epoch, found at Shirley Canal and it was described for the first time in 1924 by Knowlton. The fossil leaf is palmate, trilobed with rounded lobal sinuses and it has a leaf pattern similar to the members of the genera Kedrostis, Melothria and Zehneria. Cucurbits are represented in 23 of the 134 mosaics containing images of crop plants, several of the cucurbit images have not been found elsewhere, suggesting a diverse and highly developed local horticulture of cucurbits in Israel during the Byzantine era. Representations of mature sponge gourds are found in localities, suggestive of the high value accorded to cleanliness. The name Cucurbitaceae comes to scientific vocabulary from New Latin, from Cucurbita, the type genus, + -aceae. The genus name comes from the Classical Latin word cucurbita, gourd, bates D, Robinson R, Jeffrey C, ed. Biology and Utilization of the Cucurbitaceae. CS1 maint, Multiple names, editors list Jeffrey C, Cucurbitaceae in L. Watson and M. J. Dallwitz. The families of flowering plants, descriptions, illustrations, identification, information retrieval
9.
Cucumis
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Cucumis is a genus of twining, tendril-bearing plants in the Cucurbitaceae family which includes the cucumber, muskmelons, the horned melon, and the West Indian gherkin. Thirty species occur in Africa, and 25 occur in India, Southeast Asia, and Australia. Cucumber Melon Horned melon Bailan melon Cantaloupe Galia Hami melon Honeydew Korean melon Muskmelon Santa Claus melon Sugar melon Winter melon Ghebretinsae, A. G. Thulin, M. & Barber, relationships of cucumbers and melons unraveled, molecular phylogenetics of Cucumis and related genera. American Journal of Botany 94, 1256–1266, Renner, S. S. Schaefer, H. & Kocyan, A. Schaefer, H, Kocyan, A. Phylogenetics of Cucumis, Cucumber belongs in an Asian/Australian clade far from melon. Sebastian, P. M. H. Schaefer, I. R. H. Telford, Cucumis in Australia and eastern Malesia, including newly recognized species and the sister species to C. melo. Systematic Botany 36, 376-389 Multilingual taxonomic information at the University of Melbourne Cucumis
10.
Binomial nomenclature
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Such a name is called a binomial name, a binomen, binominal name or a scientific name, more informally it is also called a Latin name. The first part of the name identifies the genus to which the species belongs, for example, humans belong to the genus Homo and within this genus to the species Homo sapiens. The formal introduction of system of naming species is credited to Carl Linnaeus. But Gaspard Bauhin, in as early as 1623, had introduced in his book Pinax theatri botanici many names of genera that were adopted by Linnaeus. Although the general principles underlying binomial nomenclature are common to these two codes, there are differences, both in the terminology they use and in their precise rules. Similarly, both parts are italicized when a binomial name occurs in normal text, thus the binomial name of the annual phlox is now written as Phlox drummondii. In scientific works, the authority for a name is usually given, at least when it is first mentioned. In zoology Patella vulgata Linnaeus,1758, the original name given by Linnaeus was Fringilla domestica, the parentheses indicate that the species is now considered to belong in a different genus. The ICZN does not require that the name of the person who changed the genus be given, nor the date on which the change was made, in botany Amaranthus retroflexus L. – L. is the standard abbreviation used in botany for Linnaeus. – Linnaeus first named this bluebell species Scilla italica, Rothmaler transferred it to the genus Hyacinthoides, the ICN does not require that the dates of either publication be specified. Prior to the adoption of the binomial system of naming species. Together they formed a system of polynomial nomenclature and these names had two separate functions. First, to designate or label the species, and second, to be a diagnosis or description, such polynomial names may sometimes look like binomials, but are significantly different. For example, Gerards herbal describes various kinds of spiderwort, The first is called Phalangium ramosum, Branched Spiderwort, is aptly termed Phalangium Ephemerum Virginianum, Soon-Fading Spiderwort of Virginia. The Latin phrases are short descriptions, rather than identifying labels, the Bauhins, in particular Caspar Bauhin, took some important steps towards the binomial system, by pruning the Latin descriptions, in many cases to two words. The adoption by biologists of a system of binomial nomenclature is due to Swedish botanist and physician Carl von Linné. It was in his 1753 Species Plantarum that he first began using a one-word trivial name together with a generic name in a system of binomial nomenclature. This trivial name is what is now known as an epithet or specific name
11.
Carl Linnaeus
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Carl Linnaeus, also known after his ennoblement as Carl von Linné, was a Swedish botanist, physician, and zoologist, who formalised the modern system of naming organisms called binomial nomenclature. He is known by the father of modern taxonomy. Many of his writings were in Latin, and his name is rendered in Latin as Carolus Linnæus, Linnaeus was born in the countryside of Småland, in southern Sweden. He received most of his education at Uppsala University. He lived abroad between 1735 and 1738, where he studied and also published a first edition of his Systema Naturae in the Netherlands and he then returned to Sweden, where he became professor of medicine and botany at Uppsala. In the 1740s, he was sent on journeys through Sweden to find and classify plants. In the 1750s and 1760s, he continued to collect and classify animals, plants, and minerals, at the time of his death, he was one of the most acclaimed scientists in Europe. The philosopher Jean-Jacques Rousseau sent him the message, Tell him I know no man on earth. The German writer Johann Wolfgang von Goethe wrote, With the exception of Shakespeare and Spinoza, Swedish author August Strindberg wrote, Linnaeus was in reality a poet who happened to become a naturalist. Among other compliments, Linnaeus has been called Princeps botanicorum, The Pliny of the North and he is also considered as one of the founders of modern ecology. In botany, the abbreviation used to indicate Linnaeus as the authority for species names is L. In older publications, sometimes the abbreviation Linn. is found, Linnæus was born in the village of Råshult in Småland, Sweden, on 23 May 1707. He was the first child of Nicolaus Ingemarsson and Christina Brodersonia and his siblings were Anna Maria Linnæa, Sofia Juliana Linnæa, Samuel Linnæus, and Emerentia Linnæa. One of a line of peasants and priests, Nils was an amateur botanist, a Lutheran minister. Christina was the daughter of the rector of Stenbrohult, Samuel Brodersonius, a year after Linnæus birth, his grandfather Samuel Brodersonius died, and his father Nils became the rector of Stenbrohult. The family moved into the rectory from the curates house, even in his early years, Linnæus seemed to have a liking for plants, flowers in particular. Whenever he was upset, he was given a flower, which calmed him. Nils spent much time in his garden and often showed flowers to Linnaeus, soon Linnæus was given his own patch of earth where he could grow plants
12.
Gourd
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A gourd is a plant of the family Cucurbitaceae, particularly Cucurbita and Lagenaria or the fruit of the two genera of Bignoniaceae calabash tree, Crescentia and Amphitecna. The term refers to a number of species and subspecies, many with hard shells, likely one of the earliest domesticated types of plants, subspecies of the bottle gourd, Lagenaria siceraria, have been discovered in archaeological sites dating from as early as 13,000 BC. Gourds have had numerous uses throughout history, including as tools, musical instruments, objects of art, film, gourd is occasionally used to describe crop plants in the family Cucurbitaceae, like pumpkins, cucumbers, squash, luffa, and melons. More specifically, gourd refers to the fruits of plants in the two Cucurbitaceae genera Lagenaria and Cucurbita, or also to their hollow, dried-out shell, a gourd can also have a hard shell when dehydrated. There are many different gourds worldwide, the main plants referred to as gourds include several species from the Cucurbita genus, Crescentia cujete and Lagenaria siceraria. The bitter melon/balsam apple/balsam pear is also referred to as a gourd. L. siceraria was brought to Europe and the Americas very early in history, being found in Peruvian archaeological sites dating from 13,000 to 11,000 BC and Thailand sites from 11,000 to 6,000 BC. The gourds found in the Americas appear to have come from the Asian subspecies, very early in history, a new study now indicates Africa. The archaeological and DNA records show it likely that the gourd was among the first domesticated species, gourds continued to be used throughout history, in almost every culture throughout the world. European contact in North America found extensive use, including the use of bottle gourds as birdhouses to attract purple martins. Almost every culture had musical instruments made of gourds, including drums, stringed instruments common to Africa and wind instruments and these include Teasle gourd, Spine gourd, Sweet gourd, balsam apple and Momordica sahyadrica. Cultures from arid regions often associated gourds with water, and they appear in creation myths. Since the beginning of their history, they have had a multitude of uses, including food, kitchen tools, toys, musical instruments and decoration. Today, gourds are used for a wide variety of crafts, including jewelry, furniture, dishes, utensils. The Chinese developed a technique of tying a two-part mould around young gourds, or a part of them, so that the gourd grew into the mould, shaped gourds had various decorative uses, especially as boxes, bottles and other containers. The Luffa gourds, Luffa aegyptiaca and Luffa acutangula, have been used throughout recent history as scrubbing sponge and this is prepared by removing the skin and pulp from the gourd, and bleaching the fibers. A güiro is a Latin American percussion instrument made from a gourd, maracas are percussion instruments often made from gourds. A sitar is a stringed instrument, parts of which are made from gourds
13.
Vine
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A vine in the narrowest sense is the grapevine, but more generally it can refer to any plant with a growth habit of trailing or scandent stems, lianas or runners. The word also can refer to such stems or runners themselves, in the United Kingdom, the term vine applies almost exclusively to the grapevine. The term climber is used for all climbing plants, certain plants always grow as vines, while a few grow as vines only part of the time. For instance, poison ivy and bittersweet can grow as low shrubs when support is not available, a vine displays a growth form based on long stems. This has been a successful growth form for plants such as kudzu and Japanese honeysuckle. There are some tropical vines that develop skototropism, and grow away from the light, growth away from light allows the vine to reach a tree trunk, which it can then climb to brighter regions. The vine growth form may also enable plants to large areas quickly. This is the case with periwinkle and ground ivy and it is also an adaptation to life in areas where small patches of fertile soil are adjacent to exposed areas with more sunlight but little or no soil. A vine can root in the soil but have most of its leaves in the brighter, exposed area, the evolution of a climbing habit has been implicated as a key innovation associated with the evolutionary success and diversification of a number of taxonomic groups of plants. It has evolved independently in several plant families, using many different climbing methods such as and it directs its stem into a crevice in the bark of fibrous barked trees where the stem adopts a flattened profile and grows up the tree underneath the host trees outer bark. The fetterbush then sends out branches that emerge near the top of the tree and these may be divided into woody vines or lianas, such as wisteria, kiwifruit, and common ivy, and herbaceous vines, such as morning glory. One odd group of vining plants is the fern genus Lygodium, the stem does not climb, but rather the fronds do. The fronds unroll from the tip, and theoretically never stop growing, they can form thickets as they unroll over other plants, rockfaces, gardeners can use the tendency of climbing plants to grow quickly. If a plant display is wanted quickly, a climber can achieve this, climbers can be trained over walls, pergolas, fences, etc. Climbers can be grown over other plants to provide additional attraction, artificial support can also be provided. Some climbers climb by themselves, others need work, such as tying them in, vines widely differ in size, form and evolutionary origin. Darwin classified climbing groups based on their climbing method and he classified five classes of vines including twining plants, leaf climbers, tendril bearers, root climbers and hook climbers. Vines are unique in that they have multiple origins and a wide range of phenotypic plasticity
14.
Vegetable
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In everyday usage, a vegetable is any part of a plant that is consumed by humans as food as part of a meal. The term vegetable is somewhat arbitrary, and largely defined through culinary and it normally excludes other food derived from plants such as fruits, nuts, and cereal grains, but includes seeds such as pulses. The original meaning of the vegetable, still used in biology, was to describe all types of plant, as in the terms vegetable kingdom. At first, plants which grew locally would have been cultivated, nowadays, most vegetables are grown all over the world as climate permits, and crops may be cultivated in protected environments in less suitable locations. China is the largest producer of vegetables and global trade in agricultural products allows consumers to purchase vegetables grown in faraway countries, the scale of production varies from subsistence farmers supplying the needs of their family for food, to agribusinesses with vast acreages of single-product crops. Depending on the type of vegetable concerned, harvesting the crop is followed by grading, storing, processing, and marketing. Vegetables can be either raw or cooked and play an important role in human nutrition, being mostly low in fat and carbohydrates. Many nutritionists encourage people to consume plenty of fruit and vegetables, the word vegetable was first recorded in English in the early 15th century. It comes from Old French, and was applied to all plants. It derives from Medieval Latin vegetabilis growing, flourishing, a change from a Late Latin meaning to be enlivening, quickening. The meaning of vegetable as a plant grown for food was not established until the 18th century, in 1767, the word was specifically used to mean a plant cultivated for food, an edible herb or root. The year 1955 saw the first use of the shortened, slang term veggie, the broadest definition is the words use adjectivally to mean matter of plant origin to distinguish it from animal, meaning matter of animal origin. More specifically, a vegetable may be defined as any plant, part of which is used for food, a secondary meaning then being the edible part of such a plant. A more precise definition is any plant part consumed for food that is not a fruit or seed, falling outside these definitions are edible fungi and edible seaweed which, although not parts of plants, are often treated as vegetables. In everyday language, the fruit and vegetable are mutually exclusive. Fruit has a precise meaning, being a part that developed from the ovary of a flowering plant. This is considerably different from the words culinary meaning, while peaches, plums, and oranges are fruit in both senses, many items commonly called vegetables, such as eggplants, bell peppers, and tomatoes, are botanically fruits. The question of whether the tomato is a fruit or a vegetable found its way into the United States Supreme Court in 1893
15.
Pickled cucumber
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A gherkin is a variety of cucumber, the West Indian or burr gherkin, which produces a somewhat smaller fruit than the garden cucumber. Gherkins are cooked, eaten raw, or used as pickles, gherkins are usually picked when 4 to 8 cm in length and pickled in jars or cans with vinegar or brine. Cornichons are tart French pickles made from small gherkins pickled in vinegar and they traditionally accompany pâtés and cold cuts Brined pickles are prepared using the traditional process of natural fermentation in a brine which makes them grow sour. The brine concentration can vary between 20 to more than 40 grams of salt per litre of water, there is no vinegar used in the brine of naturally fermented pickled cucumbers. The fermentation process is dependent on the naturally occurring Lactobacillus bacteria that normally cover the skin of a growing cucumber. Typically, small cucumbers are placed in a glass or ceramic vessel or a wooden barrel, the container is then filled with cooled, boiled water and kept under a non-airtight cover for several weeks, depending on taste and external temperature. Traditionally stones, also sterilized by boiling, are placed on top of the cucumbers to keep them under the water, the more salt is added the more sour the cucumbers become. Since they are produced without vinegar, a film of bacteria forms on the top, but this does not indicate they have spoiled, and they do not, however, keep as long as cucumbers pickled with vinegar, and usually must be refrigerated. Some commercial manufacturers add vinegar as a preservative, a kosher dill pickle is not necessarily kosher in the sense that it has been prepared in accordance with Jewish dietary law. Rather, it is a made in the traditional manner of Jewish New York City pickle makers, with generous addition of garlic. In New York terminology, a full-sour kosher dill is one that has fully fermented, while a half-sour, given a stay in the brine, is still crisp. Elsewhere, these pickles may sometimes be termed old and new dills, dill pickles have been served in New York City since at least 1899. The Polish-style pickled cucumber is a variety developed in the parts of Europe. It has been exported worldwide and is found in the cuisines of many countries and it is sour, similar to kosher dills, but tends to be seasoned differently. It is usually preserved in wooden barrels, a cucumber only pickled for a few days is different in taste than one pickled for a longer time and is called ogórek małosolny, which literally means low-salt cucumber. This distinction is similar to the one between half- and full-sour types of kosher dills, another kind of pickled cucumber, popular in Poland, is ogórek konserwowy which is rather sweet and vinegary in taste, due to different composition of the preserving solution. It is kept in jars instead of barrels or cans, in Hungary, while regular vinegar-pickled cucumbers are made during most of the year, during the summer kovászos uborka are made without the use of vinegar. Cucumbers are placed in a vessel along with spices, water
16.
Cultivar
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The term cultivar most commonly refers to an assemblage of plants selected for desirable characteristics that are maintained during propagation. More generally, cultivar refers to the most basic classification category of cultivated plants governed by the ICNCP, most cultivars have arisen in cultivation, but a few are special selections from the wild. Popular ornamental garden plants like roses, camellias, daffodils, rhododendrons, trees used in forestry are also special selections grown for their enhanced quality and yield of timber. Cultivars form a part of Liberty Hyde Baileys broader grouping. Cultivar was coined by Bailey and it is regarded as a portmanteau of cultivated and variety. A cultivar is not the same as a variety, a taxonomic rank below subspecies. In recent times, the naming of cultivars has been complicated by the use of statutory plant patents, the International Union for the Protection of New Varieties of Plants offers legal protection of plant cultivars to people or organisations who introduce new cultivars to commerce. UPOV requires that a cultivar be distinct, uniform and stable, to be distinct, it must have characteristics that easily distinguish it from any other known cultivar. To be uniform and stable, the cultivar must retain these characteristics under repeated propagation, a cultivar is given a cultivar name, which consists of the scientific Latin botanical name followed by a cultivar epithet. The cultivar epithet is usually in a vernacular language, for example, the full cultivar name of the King Edward potato is Solanum tuberosum King Edward. The King Edward part of the name is the cultivar epithet, the origin of the term cultivar arises from the need to distinguish between wild plants and those with characteristics that have arisen in cultivation. This distinction dates back to the Greek philosopher Theophrastus, the Father of Botany, botanical historian Alan Morton notes that Theophrastus in his Enquiry into Plants had an inkling of the limits of culturally induced changes and of the importance of genetic constitution. In Species Plantarum, Linnaeus listed all the known to him. Most of the listed by Linnaeus were of garden origin rather than being wild plants. Over time there was an increasing need to distinguish between plants growing in the wild, and those with variations that had produced in cultivation. In the nineteenth century many garden-derived plants were given names, sometimes in Latin. In the twentieth century an improved international terminology was proposed for the classification and it is essentially the equivalent of the botanical variety except in respect to its origin. However, Bailey was never explicit about the etymology of the word, and it has suggested that it is a contraction of the words cultigen and variety
17.
Echinocystis
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Echinocystis is a monotypic genus in the gourd family, Cucurbitaceae. The sole species is E. lobata, commonly called wild cucumber, prickly cucumber and it is an annual, sprawling plant that is native to North America. Echinocystis lobata is a vine that produces stems that can be as long as 8 m. The stems are angular and furrowed, the leaves are alternate with long petioles, five palmate lobes and no stipules. The flowers are monoecious, with male and female blooms on the same plant. The male flowers are in long-stemmed, upright panicles, each flower has a white, or greenish-yellow, corolla with six slender lobes. The male flower has a single stamen with a yellow anther. The female flower has a stigma and is borne on a short stalk at the base of the flower panicle. The fruit is a prickly, inflated capsule up to 5 cm long with two pores and four seeds and it resembles a tiny spiny water melon, persists all winter and then opens at the bottom, liberating the seeds. This species can be distinguished from the oneseed bur cucumber by the six-lobed corolla, the native range across North America includes forty U. S. states, and nine Canadian provinces. It has also reported as an uncommon invasive species in the Örség Landscape Protection Area of Hungary near the Austrian-Slovenian border. Similarly it is reported as an alien species that grew in wetland, grassland and human effected areas of the Carei Plain natural protected area. This vine has been reported as a source and host plant for the leaf-footed bug Anasa repetita. Specimens collected in September 2006 from a E. lobata in Grant County, additionally, the pentatomid species Euschistus servus euschistoides is recorded as feeding on developing E. lobata fruit. Robertson in 1928 reported that 2 different species of parasitoid hymenopterans had been collected from E. lobata flowers in central Illinois, both the scoliid wasp Scolia bicincta and the tiphid wasp Myzinum quinquecinctum nectared on the flowers, along with a number of other flower species. The beetle species Chauliognathus pensylvanicus is listed as visiting the flowers growing in Wisconsin. E. lobata has been shown to be susceptible to bacterial wilt, the bacteria is transmitted between plants by the Striped cucumber beetle Acalymma vittatum. As the adult beetles feed they also drop frass on fresh areas of feeding which results in infection of the plant
18.
Marah (plant)
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Marah are flowering plants in the gourd family, native to western North America. They are also commonly called Old man in the ground, the genus was named for Marah in Exodus 15, 22-25, which was said to be named for the bitter water there. Except for the range of Marah gilensis in west-central Arizona and island populations. Although Marah oreganus extends inland into Idaho, all manroot species except M. gilensis are confined to areas within 300 km of the Pacific Ocean coast. The manroots are perennial plants, growing from a tuberous root. Most have stout, scabrous or hairy stems, with coiling tendrils that enable them to climb up other plants and their leaves tend to have multiple lobes, up to 7 in some species. The fruits are striking and easily recognised and they are large, and spherical, oval or cylindrical. At a minimum they are 3 cm in diameter, but can be up to 20 cm long, both leaf and fruit shape vary widely between individual plants and leaves can be particularly variable even on the same vine. The anthropomorphic common names manroot and old man derive from the swollen lobes, on old plants, the tuber can be several meters long and weigh in excess of 100 kg. Marah species hybridize freely where ranges overlap and this, in addition to leaf and fruit variability. A proper genetic analysis of Marah phylogeny has not yet been undertaken, the standard taxonomy has been based on morphological comparisons and geographic considerations. Some authors include the manroots in genus Echinocystis, the Chinook made a poultice from the gourd. The Squaxin mashed the upper stalk in water to dip aching hands, the Chehalis burned the root and mixed the resulting powder with bear grease to apply to scrofula sores. The Coast Salish made a decoction to treat disease, kidney trouble. The dried spiky fruit can be soaked in water so that the spikes can be easily removed and they are difficult to remove otherwise. The hard fruit becomes soft in water and once the spikes are gone, the tubers of M. fabaceus and M. macrocarpus contain saponins which can act as a natural soap. Tubers of M. fabaceus were crushed and thrown into bodies of water by the Kumeyaay to immobilize fish, the tubers contain megharrhin, a saponin-like glucoside. Saponins lower the tension of water allowing the formation of bubbles
19.
South Asia
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Topographically, it is dominated by the Indian Plate, which rises above sea level as Nepal and northern parts of India situated south of the Himalayas and the Hindu Kush. South Asia is bounded on the south by the Indian Ocean and on land by West Asia, Central Asia, East Asia, the current territories of Afghanistan, Bangladesh, Bhutan, Maldives, Nepal, India, Pakistan, and Sri Lanka form the countries of South Asia. The South Asian Association for Regional Cooperation is an economic cooperation organisation in the region which was established in 1985, South Asia covers about 5.1 million km², which is 11. 51% of the Asian continent or 3. 4% of the worlds land surface area. The population of South Asia is about 1.749 billion or about one fourth of the worlds population, overall, it accounts for about 39. 49% of Asias population and is home to a vast array of peoples. The area of South Asia and its extent is not clear cut as systemic. Aside from the region of South Asia, formerly part of the British Empire, there is a high degree of variation as to which other countries are included in South Asia. Modern definitions of South Asia are consistent in including Afghanistan, India, Pakistan, Bangladesh, Sri Lanka, Nepal, Bhutan, Myanmar is included by some scholars in South Asia, but in Southeast Asia by others. Some do not include Afghanistan, others question whether Afghanistan should be considered a part of South Asia or the Middle East, the mountain countries of Nepal and Bhutan, and the island countries of Sri Lanka and Maldives are generally included as well. Myanmar is often added, and by various deviating definitions based on often substantially different reasons, the British Indian Ocean Territory, the common concept of South Asia is largely inherited from the administrative boundaries of the British Raj, with several exceptions. The Aden Colony, British Somaliland and Singapore, though administered at various times under the Raj, have not been proposed as any part of South Asia. Additionally Burma was administered as part of the Raj until 1937, the 562 princely states that were protected by but not directly ruled by the Raj became administrative parts of South Asia upon joining Union of India or Dominion of Pakistan. China and Myanmar have also applied for the status of members of SAARC. This bloc of countries include two independent countries that were not part of the British Raj – Nepal, and Bhutan, Afghanistan was a British protectorate from 1878 until 1919, after the Afghans lost to the British in the Second Anglo-Afghan war. The United Nations Statistics Divisions scheme of sub-regions include all eight members of the SAARC as part of Southern Asia, population Information Network includes Afghanistan, Bangladesh, Burma, India, Nepal, Pakistan and Sri Lanka as part of South Asia. Maldives, in view of its characteristics, was admitted as a member Pacific POPIN subregional network only in principle, the Hirschman–Herfindahl index of the United Nations Economic and Social Commission for Asia and the Pacific for the region includes only the original seven signatories of SAARC. The British Indian Ocean Territory is connected to the region by a publication of Janes for security considerations, the inclusion of Myanmar in South Asia is without consensus, with many considering it a part of southeast Asia and others including it within South Asia. Afghanistan was of importance to the British colonial empire, especially after the Second Anglo-Afghan War over 1878–1880, Afghanistan remained a British protectorate until 1919, when a treaty with Vladimir Lenin included the granting of independence to Afghanistan. Following Indias partition, Afghanistan has generally included in South Asia
20.
Continent
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A continent is one of several very large landmasses on Earth. Generally identified by convention rather than any strict criteria, up to seven regions are regarded as continents. Ordered from largest in size to smallest, they are, Asia, Africa, North America, South America, Antarctica, Europe, in geology, areas of continental crust include regions covered with water. Islands are frequently grouped with a continent to divide all the worlds land into geopolitical regions. Under this scheme, most of the countries and territories in the Pacific Ocean are grouped together with the continent of Australia to form a geopolitical region called Oceania. By convention, continents are understood to be large, continuous, discrete masses of land, many of the seven most commonly recognized continents identified by convention are not discrete landmasses separated completely by water. Earths major landmasses all have coasts on a single, continuous World Ocean, the most restricted meaning of continent is that of a continuous area of land or mainland, with the coastline and any land boundaries forming the edge of the continent. From this perspective the edge of the shelf is the true edge of the continent. In this sense the islands of Great Britain and Ireland are part of Europe, while Australia, as a cultural construct, the concept of a continent may go beyond the continental shelf to include oceanic islands and continental fragments. In this way, Iceland is considered part of Europe and Madagascar part of Africa, extrapolating the concept to its extreme, some geographers group the Australasian continental plate with other islands in the Pacific into one continent called Oceania. This divides the land surface of Earth into continents or quasi-continents. The ideal criterion that each continent be a discrete landmass is commonly relaxed due to historical conventions, of the seven most globally recognized continents, only Antarctica and Australia are completely separated from other continents by ocean. Several continents are defined not as absolutely distinct bodies but as more or less discrete masses of land, Asia and Africa are joined by the Isthmus of Suez, and North and South America by the Isthmus of Panama. In both cases, there is no separation of these landmasses by water. Both these isthmuses are very narrow compared to the bulk off the landmasses they unite, North America and South America are treated as separate continents in the seven-continent model. However, they may also be viewed as a continent known as America or the Americas. This viewpoint was common in the United States until World War II and this remains the more common vision in Latin American countries, Spain, Portugal, France, Italy and Greece, where they are taught as a single continent. The criterion of a landmass is completely disregarded if the continuous landmass of Eurasia is classified as two separate continents, Europe and Asia
21.
Market (economics)
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A market is one of the many varieties of systems, institutions, procedures, social relations and infrastructures whereby parties engage in exchange. While parties may exchange goods and services by barter, most markets rely on sellers offering their goods or services in exchange for money from buyers and it can be said that a market is the process by which the prices of goods and services are established. Markets facilitate trade and enable the distribution and allocation of resources in a society, Markets allow any trade-able item to be evaluated and priced. A market emerges more or less spontaneously or may be constructed deliberately by human interaction in order to enable the exchange of rights of services, Markets can also be worldwide, for example the global diamond trade. National economies can be classified, for example as developed markets or developing markets, in mainstream economics, the concept of a market is any structure that allows buyers and sellers to exchange any type of goods, services and information. The exchange of goods or services, with or without money, is a transaction, a major topic of debate is how much a given market can be considered to be a free market, that is free from government intervention. However it is not always clear how the allocation of resources can be improved since there is always the possibility of government failure, a market is one of the many varieties of systems, institutions, procedures, social relations and infrastructures whereby parties engage in exchange. While parties may exchange goods and services by barter, most markets rely on sellers offering their goods or services in exchange for money from buyers and it can be said that a market is the process by which the prices of goods and services are established. Markets facilitate trade and enables the distribution and allocation of resources in a society, Markets allow any trade-able item to be evaluated and priced. A market sometimes emerges more or less spontaneously but is often constructed deliberately by human interaction in order to enable the exchange of rights of services. Markets of varying types can spontaneously arise whenever a party has interest in a good or service that other party can provide. Hence there can be a market for cigarettes in correctional facilities, another for chewing gum in a playground, and yet another for contracts for the future delivery of a commodity. Markets vary in form, scale, location, and types of participants, as well as the types of goods and services traded, nevertheless, violence and they apply the market dynamics to facilitate information aggregation. However, market prices may be distorted by a seller or sellers with monopoly power, such price distortions can have an adverse effect on market participants welfare and reduce the efficiency of market outcomes. Also, the level of organization and negotiating power of buyers and sellers markedly affects the functioning of the market. Markets are a system, and systems have structure, the structure of a well-functioning market is defined by the theory of perfect competition. Market failures are often associated with time-inconsistent preferences, information asymmetries, non-perfectly competitive markets, principal–agent problems, externalities, among the major negative externalities which can occur as a side effect of production and market exchange, are air pollution and environmental degradation. There exists a popular thought, especially among economists, that markets would have a structure of a perfect competition
22.
Food energy
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Food energy is chemical energy that animals derive from food and molecular oxygen through the process of cellular respiration. Humans and other animals need a minimum intake of energy to sustain their metabolism. Foods are composed chiefly of carbohydrates, fats, proteins, alcohol, water, vitamins, carbohydrates, fats, proteins, alcohol, and water represent virtually all the weight of food, with vitamins and minerals making up only a small percentage of the weight. Organisms derive food energy from carbohydrates, fats and proteins as well as organic acids, polyols. Some diet components that provide little or no energy, such as water, minerals, vitamins, cholesterol. Water, minerals, vitamins, and cholesterol are not broken down, fiber, a type of carbohydrate, cannot be completely digested by the human body. Ruminants can extract energy from the respiration of cellulose because of bacteria in their rumens. Using the International System of Units, researchers measure energy in joules or in its multiples, the kilojoule is most often used for food-related quantities. An older metric system unit of energy, still used in food-related contexts, is the calorie, more precisely. Within the European Union, both the kilocalorie and kilojoule appear on nutrition labels, in many countries, only one of the units is displayed, in the US and Canada labels spell out the unit as calorie or as Calorie. Fats and ethanol have the greatest amount of energy per gram,37 and 29 kJ/g. Proteins and most carbohydrates have about 17 kJ/g, carbohydrates that are not easily absorbed, such as fiber, or lactose in lactose-intolerant individuals, contribute less food energy. Polyols and organic acids contribute 10 kJ/g and 13 kJ/g respectively, the amount of water, fat, and fiber in foods determines those foods energy density. Theoretically, one could measure food energy in different ways, using the Gibbs free energy of combustion, however, the convention is to use the heat of the oxidation reaction, with the water substance produced being in the liquid phase. The American chemist Wilbur Atwater worked these corrections out in the late 19th century, based on the work of Atwater, it became common practice to calculate energy content of foods using 4 kcal/g for carbohydrates and proteins and 9 kcal/g for lipids. The system was improved by Annabel Merrill and Bernice Watt of the USDA. Many governments require food manufacturers to label the energy content of their products, in the European Union, manufacturers of packaged food must label the nutritional energy of their products in both kilocalories and kilojoules, when required. In Australia and New Zealand, the energy must be stated in kilojoules
23.
Carbohydrate
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A carbohydrate is a biological molecule consisting of carbon, hydrogen and oxygen atoms, usually with a hydrogen–oxygen atom ratio of 2,1, in other words, with the empirical formula Cmn. This formula holds true for monosaccharides, some exceptions exist, for example, deoxyribose, a sugar component of DNA, has the empirical formula C5H10O4. Carbohydrates are technically hydrates of carbon, structurally it is accurate to view them as polyhydroxy aldehydes and ketones. The term is most common in biochemistry, where it is a synonym of saccharide, a group that includes sugars, starch, the saccharides are divided into four chemical groups, monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Monosaccharides and disaccharides, the smallest carbohydrates, are referred to as sugars. The word saccharide comes from the Greek word σάκχαρον, meaning sugar, while the scientific nomenclature of carbohydrates is complex, the names of the monosaccharides and disaccharides very often end in the suffix -ose. For example, grape sugar is the glucose, cane sugar is the disaccharide sucrose. Carbohydrates perform numerous roles in living organisms, polysaccharides serve for the storage of energy and as structural components. The 5-carbon monosaccharide ribose is an important component of coenzymes and the backbone of the genetic molecule known as RNA, the related deoxyribose is a component of DNA. Saccharides and their derivatives include many other important biomolecules that play key roles in the system, fertilization, preventing pathogenesis, blood clotting. In food science and in informal contexts, the term carbohydrate often means any food that is particularly rich in the complex carbohydrate starch or simple carbohydrates. Often in lists of information, such as the USDA National Nutrient Database, the term carbohydrate is used for everything other than water, protein, fat, ash. This will include chemical compounds such as acetic or lactic acid, carbohydrates are found in wide variety of foods. The important sources are cereals, potatoes, sugarcane, fruits, table sugar, bread, milk, starch and sugar are the important carbohydrates in our diet. Starch is abundant in potatoes, maize, rice and other cereals, sugar appears in our diet mainly as sucrose which is added to drinks and many prepared foods such as jam, biscuits and cakes. Glucose and fructose are found naturally in fruits and some vegetables. Glycogen is carbohydrate found in the liver and muscles, cellulose in the cell wall of all plant tissue is a carbohydrate. It is important in our diet as fibre which helps to maintain a healthy digestive system, formerly the name carbohydrate was used in chemistry for any compound with the formula Cm n
24.
Sugar
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Sugar is the generic name for sweet, soluble carbohydrates, many of which are used in food. There are various types of derived from different sources. Simple sugars are called monosaccharides and include glucose, fructose, the table sugar or granulated sugar most customarily used as food is sucrose, a disaccharide of glucose and fructose. Sugar is used in prepared foods and it is added to some foods, in the body, sucrose is hydrolysed into the simple sugars fructose and glucose. Other disaccharides include maltose from malted grain, and lactose from milk, longer chains of sugars are called oligosaccharides or polysaccharides. Some other chemical substances, such as glycerol may also have a sweet taste, low-calorie food substitutes for sugar, described as artificial sweeteners, include aspartame and sucralose, a chlorinated derivative of sucrose. Sugars are found in the tissues of most plants and are present in sufficient concentrations for efficient commercial extraction in sugarcane, the world production of sugar in 2011 was about 168 million tonnes. The average person consumes about 24 kilograms of sugar each year, equivalent to over 260 food calories per person, since the latter part of the twentieth century, it has been questioned whether a diet high in sugars, especially refined sugars, is good for human health. Sugar has been linked to obesity, and suspected of, or fully implicated as a cause in the occurrence of diabetes, cardiovascular disease, dementia, macular degeneration, the etymology reflects the spread of the commodity. The English word sugar ultimately originates from the Sanskrit शर्करा, via Arabic سكر as granular or candied sugar, the contemporary Italian word is zucchero, whereas the Spanish and Portuguese words, azúcar and açúcar, respectively, have kept a trace of the Arabic definite article. The Old French word is zuchre and the contemporary French, sucre, the earliest Greek word attested is σάκχαρις. The English word jaggery, a brown sugar made from date palm sap or sugarcane juice, has a similar etymological origin – Portuguese jagara from the Sanskrit शर्करा. Sugar has been produced in the Indian subcontinent since ancient times and it was not plentiful or cheap in early times and honey was more often used for sweetening in most parts of the world. Originally, people chewed raw sugarcane to extract its sweetness, sugarcane was a native of tropical South Asia and Southeast Asia. Different species seem to have originated from different locations with Saccharum barberi originating in India and S. edule, one of the earliest historical references to sugarcane is in Chinese manuscripts dating back to 8th century BC that state that the use of sugarcane originated in India. Sugar was found in Europe by the 1st century AD, but only as an imported medicine and it is a kind of honey found in cane, white as gum, and it crunches between the teeth. It comes in lumps the size of a hazelnut, sugar is used only for medical purposes. Sugar remained relatively unimportant until the Indians discovered methods of turning sugarcane juice into granulated crystals that were easier to store, crystallized sugar was discovered by the time of the Imperial Guptas, around the 5th century AD
25.
Dietary fiber
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Dietary fiber or roughage is the indigestible portion of food derived from plants. It has two components, Soluble fiber, which dissolves in water, is readily fermented in the colon into gases and physiologically active byproducts. It delays gastric emptying which in turn can cause a feeling of fullness. Insoluble fiber, which does not dissolve in water, is inert and provides bulking, or it can be prebiotic. Bulking fibers absorb water as they move through the digestive system, Dietary fibers can act by changing the nature of the contents of the gastrointestinal tract and by changing how other nutrients and chemicals are absorbed. Some types of soluble fiber absorb water to become a gelatinous, viscous substance which is fermented by bacteria in the digestive tract, some types of insoluble fiber have bulking action and are not fermented. Lignin, a major dietary insoluble fiber source, may alter the rate, other types of insoluble fiber, notably resistant starch, are fully fermented. A novel position has been adopted by the US Department of Agriculture to include functional fibers as isolated fiber sources that may be included in the diet, the term fiber is something of a misnomer, since many types of so-called dietary fiber are not actually fibrous. Food sources of fiber are often divided according to whether they provide soluble or insoluble fiber. Plant foods contain both types of fiber in varying degrees, according to the plants characteristics, a disadvantage of a diet high in fiber is the potential for significant intestinal gas production and bloating. Originally, fiber was defined to be the components of plants that resist human digestive enzymes, the definition was later changed to also include resistant starch, along with inulin and other oligosaccharides. Official definition of dietary fiber differs a little among different institutions, Dietary fibers are found in fruits, vegetables, the exact amount of fiber contained in the food can be seen in the following table of expected fiber in USDA food groups/subgroups Dietary fiber is found in plants. While all plants contain some fiber, plants with high concentrations are generally the most practical source. Fiber-rich plants can be eaten directly, or, alternatively, they can be used to make supplements and fiber-rich processed foods. The Academy of Nutrition and Dietetics, formerly the American Dietetic Association, some plants contain significant amounts of soluble and insoluble fiber. For example, plums and prunes have a thick skin covering a juicy pulp, the skin is a source of insoluble fiber, whereas soluble fiber is in the pulp. Grapes also contain an amount of fiber. The root of the plant, or glucomannan, produces results similar to fiber
26.
Fat
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Fat is one of the three main macronutrients, along with carbohydrate and protein. Fats, also known as triglycerides, are esters of three fatty acid chains and the alcohol glycerol, the terms oil, fat, and lipid are often confused. Oil normally refers to a fat with short or unsaturated fatty acid chains that is liquid at room temperature, lipid is the general term, as a lipid is not necessarily a triglyceride. Fats, like lipids, are generally hydrophobic, and are soluble in organic solvents. Fat is an important foodstuff for many forms of life, and they are a necessary part of the diet of most heterotrophs. Some fatty acids that are set free by the digestion of fats are called essential because they cannot be synthesized in the body from simpler constituents, there are two essential fatty acids in human nutrition, alpha-linolenic acid and linoleic acid. Other lipids needed by the body can be synthesized from these, fats and other lipids are broken down in the body by enzymes called lipases produced in the pancreas. Fats and oils are categorized according to the number and bonding of the atoms in the aliphatic chain. Fats that are saturated fats have no double bonds between the carbons in the chain, unsaturated fats have one or more double bonded carbons in the chain. The nomenclature is based on the end of the chain. This end is called the end or the n-end. Thus alpha-linolenic acid is called an omega-3 fatty acid because the 3rd carbon from that end is the first double bonded carbon in the counting from that end. Some oils and fats have double bonds and are therefore called polyunsaturated fats. Unsaturated fats can be divided into cis fats, which are the most common in nature, and trans fats. Unsaturated fats can be altered by reaction with hydrogen effected by a catalyst and this action, called hydrogenation, tends to break all the double bonds and makes a fully saturated fat. However, trans fats are generated during hydrogenation as contaminants created by a side reaction on the catalyst during partial hydrogenation. Saturated fats can stack themselves in a closely packed arrangement, so they can easily and are typically solid at room temperature. For example, animal fats tallow and lard are high in saturated fatty acid content and are solids, olive and linseed oils on the other hand are unsaturated and liquid
27.
Protein (nutrient)
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Proteins are essential nutrients for the human body. They are one of the blocks of body tissue. As a fuel, proteins provide as much energy density as carbohydrates,4 kcal per gram, in contrast, the most important aspect and defining characteristic of protein from a nutritional standpoint is its amino acid composition. Proteins are polymer chains made of amino acids linked together by peptide bonds, during human digestion, proteins are broken down in the stomach to smaller polypeptide chains via hydrochloric acid and protease actions. This is crucial for the synthesis of the amino acids that cannot be biosynthesized by the body. There are nine amino acids which humans must obtain from their diet in order to prevent protein-energy malnutrition. They are phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, there are five dispensable amino acids which humans are able to synthesize in the body. These five are alanine, aspartic acid, asparagine, glutamic acid and these six are arginine, cysteine, glycine, glutamine, proline and tyrosine. Humans need the essential amino acids in certain ratios, some protein sources contain amino acids in a more or less complete sense. This has given rise to various ranking systems for protein sources, Dietary sources of protein include both animals and plants, meats, dairy products, fish and eggs as well as grains, legumes and nuts. Vegetarians and vegans can get enough essential amino acids by eating a variety of plant proteins and it is commonly believed that athletes should consume a higher-than-normal protein intake to maintain optimal physical performance. Protein is a nutrient needed by the body for growth. Aside from water, proteins are the most abundant kind of molecules in the body, Protein can be found in all cells of the body and is the major structural component of all cells in the body, especially muscle. This also includes body organs, hair and skin, proteins are also used in membranes, such as glycoproteins. When broken down into amino acids, they are used as precursors to acid, co-enzymes, hormones, immune response, cellular repair. Additionally, protein is needed to form blood cells, proteins are believed to increase performance in terms of athletics. Amino acids, the blocks of proteins, are used for building muscle tissue. Protein is only used as fuel when carbohydrates are low
28.
Vitamin
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A vitamin is an organic compound and a vital nutrient that an organism requires in limited amounts. For example, ascorbic acid is a vitamin for humans, supplementation is important for the treatment of certain health problems, but there is little evidence of nutritional benefit when used by otherwise healthy people. Thirteen vitamins are universally recognized at present, Vitamins are classified by their biological and chemical activity, not their structure. Thus, each vitamin refers to a number of compounds that all show the biological activity associated with a particular vitamin. Such a set of chemicals is grouped under an alphabetized vitamin generic descriptor title, such as vitamin A, which includes the compounds retinal, retinol, and four known carotenoids. Vitamers by definition are convertible to the form of the vitamin in the body. Some, such as vitamin D, have hormone-like functions as regulators of mineral metabolism, or regulators of cell and tissue growth and differentiation. The largest number of vitamins, the B complex vitamins, function as cofactors or the precursors for them. In this role, vitamins may be bound to enzymes as part of prosthetic groups, For example. They may also be less tightly bound to enzyme catalysts as coenzymes, for example, folic acid may carry methyl, formyl, and methylene groups in the cell. Although these roles in assisting enzyme-substrate reactions are vitamins best-known function, study of structural activity, function and their role in maintaining health is called vitaminology. Each vitamin is typically used in reactions, and therefore most have multiple functions. Vitamins are essential for the growth and development of a multicellular organism. Using the genetic blueprint inherited from its parents, a fetus begins to develop from the nutrients it absorbs and it requires certain vitamins and minerals to be present at certain times. These nutrients facilitate the chemical reactions that produce among other things, skin, bone, if there is serious deficiency in one or more of these nutrients, a child may develop a deficiency disease. Even minor deficiencies may cause permanent damage, for the most part, vitamins are obtained with food, but a few are obtained by other means. Humans can produce some vitamins from precursors they consume, examples include vitamin A, produced from beta carotene, and niacin, from the amino acid tryptophan. In those who are healthy, there is little evidence that supplements have any benefits with respect to cancer or heart disease
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Folate
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Folic acid, another form of which is known as folate, is one of the B vitamins. The recommended daily level of folate is 400 micrograms from foods or dietary supplements. Folic acid is used to treat anemia caused by folic acid deficiency and it is also used as a supplement by women during pregnancy to prevent neural tube defects in the baby. Low levels in early pregnancy are believed to be the cause of more than half of babies born with neural tube defects, more than 50 countries use fortification of certain foods with folic acid as a measure to decrease the rate of NTDs in the population. Long term supplementation is also associated with reductions in the risk of stroke. It may be taken by mouth or by injection, there are no common side effects. It is not known whether high doses over a period of time are of concern. There are concerns that large amounts of folic acid might hide vitamin B12 deficiency, folic acid is essential for the body to make DNA, RNA, and metabolise amino acids which are required for cell division. As humans cannot make folic acid, it is required from the diet, not consuming enough folate can lead to folate deficiency. This may result in a type of anemia in which low numbers of red blood cells occur. Symptoms may include feeling tired, heart palpitations, shortness of breath, open sores on the tongue, deficiency in children may develop within a month of poor dietary intake. In adults normal total body folate is between 10, 000–30,000 micrograms with blood levels of greater than 7 nmol/L, folic acid was discovered between 1931 and 1943. It is on the World Health Organizations List of Essential Medicines, the wholesale cost of supplements in the developing world is between 0.001 and 0.005 USD per dose as of 2014. The term folic is from the Latin word folium, which means leaf, folates occur naturally in many foods especially dark green leafy vegetables and liver. Other names include vitamin B9, vitamin Bc, vitamin M, folacin, folic acid intake during pregnancy has been linked to a lessened risk of neural tube defects. Likewise, a meta-analysis of folic acid supplementation during pregnancy reported a 28% lower risk of congenital heart defects. The United States Preventive Services Task Force recommends folic acid supplementation for all able to become pregnant. Prenatal supplementation did not appear to reduce the risk of pre-term births, and there does not appear to be a correlation between maternal folic acid supplementation and an increased risk for asthma in the child
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Vitamin C
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Vitamin C, also known as ascorbic acid and L-ascorbic acid, is a vitamin found in food and used as a dietary supplement. As a supplement it is used to treat and prevent scurvy, evidence does not support use in the general population for the prevention of the common cold. It may be taken by mouth or by injection, large doses may cause gastrointestinal discomfort, headache, trouble sleeping, and flushing of the skin. Normal doses are safe during pregnancy, Vitamin C is an essential nutrient involved in the repair of tissue. Foods that contain vitamin C include citrus fruit, tomatoes, Vitamin C was discovered in 1912, isolated in 1928, and first made in 1933. It is on the World Health Organizations List of Essential Medicines, Vitamin C is available as a generic medication and over the counter. In 2015, the wholesale cost in the world was about 0.003 to 0.007 USD per tablet. In some countries, ascorbic acid may be added to such as breakfast cereal. A2012 Cochrane review found no effect of vitamin C supplementation on overall mortality, although rare in modern times, scurvy and its associated destabilization of collagen, connective tissue, and bone can be prevented by adequate vitamin C intake. A2014 review found that, Currently, the use of high-dose IV vitamin C cannot be recommended outside of a clinical trial, a 2013 Cochrane review found no evidence that vitamin C supplementation reduces the risk of lung cancer in healthy or high risk people. A2014 meta-analysis found that vitamin C intake might protect against lung cancer risk, a second meta-analysis found no effect on the risk of prostate cancer. Two meta-analyses evaluated the effect of vitamin C supplementation on the risk of colorectal cancer, one found a weak association between vitamin C consumption and reduced risk, and the other found no effect of supplementation. A2013 meta-analysis found no evidence that vitamin C supplementation reduces the risk of myocardial infarction, stroke, cardiovascular mortality, however, a second analysis found an inverse relationship between circulating vitamin C levels or dietary vitamin C and the risk of stroke. A meta-analysis of 44 clinical trials has shown a significant positive effect of vitamin C on endothelial function when taken at doses greater than 500 mg per day. The researchers noted that the effect of vitamin C supplementation appeared to be dependent on health status, a 2010 review found no role for vitamin C supplementation in the treatment of rheumatoid arthritis. Studies examining the effects of vitamin C intake on the risk of Alzheimers disease have reached conflicting conclusions, maintaining a healthy dietary intake is probably more important than supplementation for achieving any potential benefit. Vitamin C supplementation above the RDA has been used in trials to study a potential effect on preventing and slowing the progression of age-related cataract, however, no significant effects were found from the research. Vitamin Cs effect on the cold has been extensively researched
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Calcium in biology
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Calcium ions play a vital role in the physiology and biochemistry of organisms and the cell. Many enzymes require calcium ions as a cofactor, those of the blood-clotting cascade being notable examples, extracellular calcium is also important for maintaining the potential difference across excitable cell membranes, as well as proper bone formation. Calcium levels in mammals are tightly regulated, with acting as the major mineral storage site. Calcium ions, Ca2+, are released from bone into the bloodstream under controlled conditions, calcium is transported through the bloodstream as dissolved ions or bound to proteins such as serum albumin. Calcitriol, the form of vitamin D3, promotes absorption of calcium from the intestines. Calcitonin secreted from the cells of the thyroid gland also affects calcium levels by opposing parathyroid hormone, however. Calcium storages are intracellular organelles, that constantly accumulate Ca2+ ions, intracellular Ca2+ storages include mitochondria and the endoplasmic reticulum. Characteristic concentrations of calcium in model organisms are, in E. coli 3mM, 100nM, in budding yeast 2mM, in mammalian cell 10-100nM and this is evidenced by human plasma calcium, which is one of the most closely regulated physiological variables in the human body. Normal plasma levels vary between 1 and 2% over any given time, different tissues contain calcium in different concentrations. For instance, Ca2+ is the most important element of bone, in humans, the total body content of calcium is present mostly in the form of bone mineral. In this state, it is unavailable for exchange/bioavailability. The way to overcome this is through the process of bone resorption, the remainder of calcium is present within the extracellular and intracellular fluids. Within a typical cell, the concentration of ionized calcium is roughly 100 nM. The intracellular calcium level is relatively low with respect to the extracellular fluid, by an approximate magnitude of 12. This gradient is maintained through various plasma membrane calcium pumps that utilize ATP for energy, in electrically excitable cells, such as skeletal and cardiac muscles and neurons, membrane depolarization leads to a Ca2+ transient with cytosolic Ca2+ concentration reaching 400 nM and above. Mitochondria are capable of sequestering and storing some of that Ca2+ and it has been estimated that mitochondrial matrix free calcium concentration rises to the tens of micromolar levels in situ during neuronal activity. The effects of calcium on human cells are specific, meaning that different types of cells respond in different ways, however, in certain circumstances, its action may be more general. Ca2+ ions are one of the most widespread second messengers used in signal transduction, levels of intracellular calcium are regulated by transport proteins that remove it from the cell
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Human iron metabolism
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Human iron metabolism is the set of chemical reactions maintaining human homeostasis of iron at both the systemic and cellular level. The control of this necessary but potentially toxic metal is an important part of many aspects of human health, hematologists have been especially interested in systemic iron metabolism because iron is essential for red blood cells, where most of the human bodys iron is contained. Understanding iron metabolism is also important for understanding diseases of iron overload, such as hereditary hemochromatosis, iron is an essential bioelement for most forms of life, from bacteria to mammals. Its importance lies in its ability to mediate electron transfer, in the ferrous state, iron acts as an electron donor, while in the ferric state it acts as an acceptor. Thus, iron plays a role in the catalysis of enzymatic reactions that involve electron transfer. Proteins can contain iron as part of different cofactors, such as clusters and heme groups. Human cells require iron in order to obtain energy as ATP from a process known as cellular respiration. Iron is present in the clusters and heme groups of the electron transport chain proteins that generate a proton gradient that allows ATP synthase to synthesize ATP. Heme groups are part of hemoglobin, a found in red blood cells that serves to transport oxygen from the lungs to the tissues. Heme groups are present in myoglobin to store and diffuse oxygen in muscle cells. The human body needs iron for oxygen transport, oxygen is required for the functioning and survival of nearly all cell types. Oxygen is transported from the lungs to the rest of the bound to the heme group of hemoglobin in erythrocytes. In muscles cells, iron binds myoglobin, which regulates its release and its ability to donate and accept electrons means that it can catalyze the conversion of hydrogen peroxide into free radicals. Free radicals can cause damage to a variety of cellular structures. Iron bound to proteins or cofactors such as heme is safe, also, there are virtually no truly free iron ions in the cell, since they readily form complexes with organic molecules. However, some of the iron is bound to low-affinity complexes. Iron in such complexes can cause damage as described above, to prevent that kind of damage, all life forms that use iron bind the iron atoms to proteins. This binding allows cells to benefit from iron while also limiting its ability to do harm, in mammalian cells, intracellular labile iron concentrations are typically smaller than 1 micromolar, less than 5 percent of total cellular iron
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Magnesium in biology
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Magnesium is an essential element in biological systems. Magnesium occurs typically as the Mg2+ ion and it is an essential mineral nutrient for life and is present in every cell type in every organism. For example, ATP, the source of energy in cells. What is called ATP is often actually Mg-ATP, as such, magnesium plays a role in the stability of all polyphosphate compounds in the cells, including those associated with the synthesis of DNA and RNA. Over 300 enzymes require the presence of ions for their catalytic action, including all enzymes utilizing or synthesizing ATP. In plants, magnesium is necessary for synthesis of chlorophyll and photosynthesis, a balance of magnesium is vital to the well-being of all organisms. Magnesium is a relatively abundant ion in Earths crust and mantle and is highly bioavailable in the hydrosphere and this availability, in combination with a useful and very unusual chemistry, may have led to its utilization in evolution as an ion for signaling, enzyme activation, and catalysis. However, the nature of ionic magnesium has also led to a major challenge in the use of the ion in biological systems. Biological membranes are impermeable to magnesium, so transport proteins must facilitate the flow of magnesium, chlorophyll in plants converts water to oxygen as O2. Hemoglobin in vertebrate animals transports oxygen as O2 in the blood, chlorophyll is very similar to hemoglobin, except magnesium is at the center of the chlorophyll molecule and iron is at the center of the hemoglobin molecule, with other variations. This process keeps living cells on earth alive and produces levels of CO2 and O2 in our atmosphere that has changed with industrialization. Acute deficiency is rare, and is common as a drug side-effect than from low food intake per se. The most common symptom of excess oral magnesium intake is diarrhea, since the kidneys of adult humans excrete excess magnesium efficiently, oral magnesium poisoning in adults with normal renal function is very rare. Infants, which have less ability to excrete excess magnesium even when healthy, should not be given magnesium supplements, pharmaceutical preparations with magnesium are used to treat conditions including magnesium deficiency and hypomagnesemia, as well as eclampsia. Such preparations are usually in the form of sulfate or chloride when given parenterally. Magnesium is absorbed with reasonable efficiency by the body from any soluble magnesium salt, Magnesium is similarly absorbed from Epsom salts, although the sulfate in these salts adds to their laxative effect at higher doses. The Food and Nutrition Board of the U. S, institute of Medicine updated Estimated Average Requirements and Recommended Dietary Allowances for magnesium in 1997. The current EARs for magnesium for women and men ages 31 and up are 265 mg/day and 350 mg/day, the RDAs are 320 and 420 mg/day
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Manganese
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Manganese is a chemical element with symbol Mn and atomic number 25. It is not found as an element in nature, it is often found in minerals in combination with iron. Manganese is a metal with important industrial metal alloy uses, particularly in stainless steels, by the mid-18th century, Swedish chemist Carl Wilhelm Scheele had used pyrolusite to produce chlorine. Scheele and others were aware that pyrolusite contained a new element, johan Gottlieb Gahn was the first to isolate an impure sample of manganese metal in 1774, which he did by reducing the dioxide with carbon. Manganese phosphating is used for rust and corrosion prevention on steel, ionized manganese is used industrially as pigments of various colors, which depend on the oxidation state of the ions. The permanganates of alkali and alkaline earth metals are powerful oxidizers, Manganese dioxide is used as the cathode material in zinc-carbon and alkaline batteries. In biology, manganese ions function as cofactors for a variety of enzymes with many functions. Manganese enzymes are essential in detoxification of superoxide free radicals in organisms that must deal with elemental oxygen. Manganese also functions in the complex of photosynthetic plants. The element is a trace mineral for all known living organisms but is a neurotoxin. In larger amounts, and apparently with far greater effectiveness through inhalation, Manganese is a silvery-gray metal that resembles iron. It is hard and very brittle, difficult to fuse, Manganese metal and its common ions are paramagnetic. Manganese tarnishes slowly in air and oxidizes like iron in water containing dissolved oxygen, naturally occurring manganese is composed of one stable isotope, 55Mn. Eighteen radioisotopes have been isolated and described, the most stable being 53Mn with a half-life of 3.7 million years, 54Mn with a half-life of 312.3 days, and 52Mn with a half-life of 5.591 days. All of the radioactive isotopes have half-lives of less than three hours, and the majority of less than one minute. Manganese also has three meta states, Manganese is part of the iron group of elements, which are thought to be synthesized in large stars shortly before the supernova explosion. 53Mn decays to 53Cr with a half-life of 3.7 million years, because of its relatively short half-life, 53Mn is relatively rare, produced by cosmic rays impact on iron. Manganese isotopic contents are combined with chromium isotopic contents and have found application in isotope geology
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Phosphorus
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Phosphorus is a chemical element with symbol P and atomic number 15. As an element, phosphorus exists in two major forms—white phosphorus and red phosphorus—but because it is reactive, phosphorus is never found as a free element on Earth. At 0. 099%, phosphorus is the most abundant pnictogen in the Earths crust, with few exceptions, minerals containing phosphorus are in the maximally oxidised state as inorganic phosphate rocks. The glow of phosphorus itself originates from oxidation of the white phosphorus — a process now termed chemiluminescence, together with nitrogen, arsenic, antimony, and bismuth, phosphorus is classified as a pnictogen. Phosphates are a component of DNA, RNA, ATP, and the phospholipids, demonstrating the link between phosphorus and life, elemental phosphorus was first isolated from human urine, and bone ash was an important early phosphate source. Phosphate mines contain fossils, especially marine fossils, because phosphate is present in the deposits of animal remains. Low phosphate levels are an important limit to growth in aquatic systems. The vast majority of compounds produced are consumed as fertilisers. Phosphate is needed to replace the phosphorus that plants remove from the soil, other applications include the role of organophosphorus compounds in detergents, pesticides, and nerve agents. Phosphorus exists as several forms that exhibit different properties. The two most common allotropes are white phosphorus and red phosphorus, from the perspective of applications and chemical literature, the most important form of elemental phosphorus is white phosphorus, often abbreviated as WP. It is a soft and waxy solid consists of tetrahedral P4 molecules. This P4 tetrahedron is also present in liquid and gaseous phosphorus up to the temperature of 800 °C when it starts decomposing to P2 molecules, White phosphorus exists in two crystalline forms, α and β. At room temperature, the α-form is stable, which is common and it has cubic crystal structure and at 195.2 K, it transforms into β-form. These forms differ in terms of the orientations of the constituent P4 tetrahedra. White phosphorus is the least stable, the most reactive, the most volatile, the least dense, White phosphorus gradually changes to red phosphorus. This transformation is accelerated by light and heat, and samples of white phosphorus almost always some red phosphorus. For this reason, white phosphorus that is aged or otherwise impure is also called yellow phosphorus, when exposed to oxygen, white phosphorus glows in the dark with a very faint tinge of green and blue
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Zinc
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Zinc is a chemical element with the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table, in some respects zinc is chemically similar to magnesium, both elements exhibit only one normal oxidation state, and the Zn2+ and Mg2+ ions are of similar size. Zinc is the 24th most abundant element in Earths crust and has five stable isotopes, the most common zinc ore is sphalerite, a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States, Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity. Zinc metal was not produced on a large scale until the 12th century in India and was unknown to Europe until the end of the 16th century, the mines of Rajasthan have given definite evidence of zinc production going back to the 6th century BC. To date, the oldest evidence of pure zinc comes from Zawar, in Rajasthan, alchemists burned zinc in air to form what they called philosophers wool or white snow. The element was named by the alchemist Paracelsus after the German word Zinke. German chemist Andreas Sigismund Marggraf is credited with discovering pure metallic zinc in 1746, work by Luigi Galvani and Alessandro Volta uncovered the electrochemical properties of zinc by 1800. Corrosion-resistant zinc plating of iron is the application for zinc. Other applications are in batteries, small non-structural castings. A variety of compounds are commonly used, such as zinc carbonate and zinc gluconate, zinc chloride, zinc pyrithione, zinc sulfide. Zinc is an essential mineral perceived by the public today as being of exceptional biologic and public health importance, Zinc deficiency affects about two billion people in the developing world and is associated with many diseases. In children, deficiency causes growth retardation, delayed sexual maturation, infection susceptibility, enzymes with a zinc atom in the reactive center are widespread in biochemistry, such as alcohol dehydrogenase in humans. Consumption of excess zinc can cause ataxia, lethargy and copper deficiency, Zinc is a bluish-white, lustrous, diamagnetic metal, though most common commercial grades of the metal have a dull finish.6 pm. The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150 °C, above 210 °C, the metal becomes brittle again and can be pulverized by beating. Zinc is a conductor of electricity. For a metal, zinc has relatively low melting and boiling points, the melting point is the lowest of all the transition metals aside from mercury and cadmium. Many alloys contain zinc, including brass, Other metals long known to form binary alloys with zinc are aluminium, antimony, bismuth, gold, iron, lead, mercury, silver, tin, magnesium, cobalt, nickel, tellurium, and sodium
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Kilogram
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The kilogram or kilogramme is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype of the Kilogram. The avoirdupois pound, used in both the imperial and US customary systems, is defined as exactly 0.45359237 kg, making one kilogram approximately equal to 2.2046 avoirdupois pounds. Other traditional units of weight and mass around the world are also defined in terms of the kilogram, the gram, 1/1000 of a kilogram, was provisionally defined in 1795 as the mass of one cubic centimeter of water at the melting point of ice. The final kilogram, manufactured as a prototype in 1799 and from which the IPK was derived in 1875, had an equal to the mass of 1 dm3 of water at its maximum density. The kilogram is the only SI base unit with an SI prefix as part of its name and it is also the only SI unit that is still directly defined by an artifact rather than a fundamental physical property that can be reproduced in different laboratories. Three other base units and 17 derived units in the SI system are defined relative to the kilogram, only 8 other units do not require the kilogram in their definition, temperature, time and frequency, length, and angle. At its 2011 meeting, the CGPM agreed in principle that the kilogram should be redefined in terms of the Planck constant, the decision was originally deferred until 2014, in 2014 it was deferred again until the next meeting. There are currently several different proposals for the redefinition, these are described in the Proposed Future Definitions section below, the International Prototype Kilogram is rarely used or handled. In the decree of 1795, the term gramme thus replaced gravet, the French spelling was adopted in the United Kingdom when the word was used for the first time in English in 1797, with the spelling kilogram being adopted in the United States. In the United Kingdom both spellings are used, with kilogram having become by far the more common, UK law regulating the units to be used when trading by weight or measure does not prevent the use of either spelling. In the 19th century the French word kilo, a shortening of kilogramme, was imported into the English language where it has used to mean both kilogram and kilometer. In 1935 this was adopted by the IEC as the Giorgi system, now known as MKS system. In 1948 the CGPM commissioned the CIPM to make recommendations for a practical system of units of measurement. This led to the launch of SI in 1960 and the subsequent publication of the SI Brochure, the kilogram is a unit of mass, a property which corresponds to the common perception of how heavy an object is. Mass is a property, that is, it is related to the tendency of an object at rest to remain at rest, or if in motion to remain in motion at a constant velocity. Accordingly, for astronauts in microgravity, no effort is required to hold objects off the cabin floor, they are weightless. However, since objects in microgravity still retain their mass and inertia, the ratio of the force of gravity on the two objects, measured by the scale, is equal to the ratio of their masses. On April 7,1795, the gram was decreed in France to be the weight of a volume of pure water equal to the cube of the hundredth part of the metre
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