1.
Poaceae
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Poaceae or Gramineae is a large and nearly ubiquitous family of monocotyledonous flowering plants known as grasses. Poaceae includes the cereal grasses, bamboos and the grasses of natural grassland and cultivated lawns, Grasses have stems that are hollow except at the nodes and narrow alternate leaves borne in two ranks. The lower part of each leaf encloses the stem, forming a leaf-sheath, with ca 780 genera and around 12,000 species, Poaceae are the fifth-largest plant family, following the Asteraceae, Orchidaceae, Fabaceae and Rubiaceae. Grasslands such as savannah and prairie grasses are dominant are estimated to constitute 40. 5% of the land area of the Earth, excluding Greenland. Grasses are also an important part of the vegetation in many habitats, including wetlands, forests. Though commonly called grasses, seagrasses, rushes, and sedges fall outside this family, the rushes and sedges are related to the Poaceae, being members of the order Poales, but the seagrasses are members of order Alismatales. The name Poaceae was given by John Hendley Barnhart in 1895, based on the tribe Poeae described in 1814 by Robert Brown, the term is derived from the Ancient Greek πόα. Grasses include some of the most versatile plant life-forms, a cladogram shows subfamilies and approximate species numbers in brackets, Before 2005, fossil findings indicated that grasses evolved around 55 million years ago. Recent findings of grass-like phytoliths in Cretaceous dinosaur coprolites have pushed this back to 66 million years ago. In 2011, revised dating of the origins of the rice tribe Oryzeae suggested a date as early as 107 to 129 Mya, a multituberculate mammal with grass-eating adaptations seems to suggest that grasses were already around at 120 mya. This separation occurred within the short time span of about 4 million years. Grass leaves are always alternate and distichous, and have parallel veins. Each leaf is differentiated into a lower sheath hugging the stem, the leaf blades of many grasses are hardened with silica phytoliths, which discourage grazing animals, some, such as sword grass, are sharp enough to cut human skin. A membranous appendage or fringe of hairs called the ligule lies at the junction between sheath and blade, preventing water or insects from penetrating into the sheath, flowers of Poaceae are characteristically arranged in spikelets, each having one or more florets. The spikelets are further grouped into panicles or spikes, the part of the spikelet that bears the florets is called the rachilla. A spikelet consists of two bracts at the base, called glumes, followed by one or more florets, a floret consists of the flower surrounded by two bracts, one external—the lemma—and one internal—the palea. The flowers are usually hermaphroditic—maize being an important exception—and anemophilous or wind-pollinated, the perianth is reduced to two scales, called lodicules, that expand and contract to spread the lemma and palea, these are generally interpreted to be modified sepals. This complex structure can be seen in the image on the right, the fruit of grasses is a caryopsis, in which the seed coat is fused to the fruit wall
2.
Leaf
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A leaf is an organ of a vascular plant and is the principal lateral appendage of the stem. The leaves and stem together form the shoot, Leaves are collectively referred to as foliage, as in autumn foliage. Although leaves can be seen in different shapes, sizes and textures, typically a leaf is a thin, dorsiventrally flattened organ, borne above ground. Most leaves have distinctive upper surface and lower surface that differ in colour, hairiness, broad, flat leaves with complex venation are known as megaphylls and the species that bear them, the majority, as broad-leaved or megaphyllous plants. In others, such as the clubmosses, with different evolutionary origins, some leaves, such as bulb scales are not above ground, and in many aquatic species the leaves are submerged in water. Succulent plants often have thick juicy leaves, but some leaves are without major photosynthetic function and may be dead at maturity, as in some cataphylls, furthermore, several kinds of leaf-like structures found in vascular plants are not totally homologous with them. Examples include flattened plant stems called phylloclades and cladodes, and flattened leaf stems called phyllodes which differ from both in their structure and origin. Many structures of plants, such as the phyllids of mosses and liverworts and even of some foliose lichens. Leaves are the most important organs of most vascular plants and these are then further processed by chemical synthesis into more complex organic molecules such as cellulose, the basic structural material in plant cell walls. The plant must therefore bring these three together in the leaf for photosynthesis to take place. Once sugar has been synthesized, it needs to be transported to areas of growth such as the plant shoots and roots. Vascular plants transport sucrose in a tissue called the phloem. The phloem and xylem are parallel to each other but the transport of materials is usually in opposite directions. Within the leaf these vascular systems branch to form veins which supply as much as the leaf as possible and they are arranged on the plant so as to expose their surfaces to light as efficiently as possible without shading each other, but there are many exceptions and complications. For instance plants adapted to windy conditions may have pendent leaves, such as in many willows, the flat, or laminar, shape also maximises thermal contact with the surrounding air, promoting cooling. Functionally, in addition to photosynthesis the leaf is the site of transpiration and guttation. Many gymnosperms have thin needle-like or scale-like leaves that can be advantageous in cold climates with frequent snow and these are interpreted as reduced from megaphyllous leaves of their Devonian ancestors. For xerophytes the major constraint is not light flux or intensity, some window plants such as Fenestraria species and some Haworthia species such as Haworthia tesselata and Haworthia truncata are examples of xerophytes. and Bulbine mesembryanthemoides
3.
Tomato
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The tomato is the edible fruit of Solanum lycopersicum, commonly known as a tomato plant, which belongs to the nightshade family, Solanaceae. The species originated in Central and South America, the Nahuatl word tomatl gave rise to the Spanish word tomate, from which the English word tomato originates. Numerous varieties of tomato are widely grown in temperate climates across the world, with greenhouses allowing its production throughout the year, the plants typically grow to 1–3 meters in height and have a weak stem that often sprawls over the ground and vines over other plants. It is a perennial in its habitat, and grown as an annual in temperate climates. An average common tomato weighs approximately 100 grams and its use as a food originated in Mexico, and spread throughout the world following the Spanish colonization of the Americas. Tomato is consumed in diverse ways, including raw, as an ingredient in dishes, sauces, salads. While tomatoes are botanically fruits, they are considered culinary vegetables. The word tomato comes from the Spanish tomate, which in turn comes from the Nahuatl word tomatl and it first appeared in print in 1595. The native Mexican tomatillo is tomate, meaning fat water or fat thing), when Aztecs started to cultivate the Andean fruit, bigger and red, they called the new species xitomatl. It first appeared in print in 1595, the scientific species epithet lycopersicum means wolf peach, and comes from German werewolf myths. The Italian word, pomodoro was borrowed into Polish, and via Russian, the usual pronunciations of tomato are /təˈmeɪtoʊ/ and /təˈmɑːtoʊ/. The words dual pronunciations were immortalized in Ira and George Gershwins 1937 song Lets Call the Whole Thing Off and have become a symbol for nitpicking pronunciation disputes. In this capacity, it has become an American and British slang term. Or Its all the same to me, botanically, a tomato is a fruit, a berry, consisting of the ovary, together with its seeds, of a flowering plant. However, the tomato has a lower sugar content than other edible fruits. Typically served as part of a salad or main course of a meal, rather than at dessert, it is, in the US, considered a culinary vegetable. One exception is that tomatoes are treated as a fruit in home canning practices, they are acidic enough to process in a water bath rather than a pressure cooker as vegetables require. Tomatoes are not the food source with this ambiguity, bell peppers, cucumbers, green beans, eggplants, avocados
4.
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
5.
Predation
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In an ecosystem, predation is a biological interaction where a predator feeds on its prey. Predators may or may not kill their prey prior to feeding on it, but the act of predation often results in the death of the prey, thus predation is often, though not always, carnivory. Other categories of consumption are herbivory, fungivory, and detritivory, all of these are consumer-resource systems. It can often be difficult to separate various types of feeding behaviors. For example, some parasites prey on their host and then lay their eggs on it, for their offspring to feed on it while it continues to live, the key characteristic of predation is the predators direct impact on the prey population. Selective pressures imposed on one another leads to an evolutionary arms race between prey and predator, resulting in various antipredator adaptations. Ways of classifying predation include grouping by trophic level or diet, by specialization, Predators can be classified by their interactions with their prey. Two factors are considered here, how close the predator and prey are, and whether the prey is killed by the predator. A true predator is one that kills and eats another living thing, Predators may hunt actively for prey in pursuit predation, or sit and wait for prey to approach within striking distance, as in ambush predators. Some predation entails venom that subdues a prey before the predator ingests it, as in the box jellyfish, or disables it, in some cases, the venom contributes to the digestion of the prey, as in rattlesnakes and some spiders. In contrast, baleen whales eat millions of microscopic plankton at once, seed and egg predation are true predation, as seeds and eggs are potential organisms. Predators need not eat prey entirely, for example, some predators cannot digest bones, some may eat only part of an organism, but still consistently cause its death. Grazing organisms do not often kill their prey, while some herbivores like zooplankton live on unicellular phytoplankton and therefore, by the individualized nature of the organism, kill their prey, many others only eat a small part of the plant. Grazing livestock may pull some grass out at the roots, but most is simply grazed upon, kelp is frequently grazed in subtidal kelp forests, but regrows at the base of the blade continuously to cope with browsing pressure. Animals may also be grazed upon, female mosquitos land on hosts briefly to gain sufficient proteins for the development of their offspring, starfish may be grazed on, being capable of regenerating lost arms. Parasites can at times be difficult to distinguish from grazers and their feeding behavior is similar in many ways, however they are noted for their close association with their host species. This close living arrangement may be described by the symbiosis, living together. Parasitic organisms range from the mistletoe, a parasitic plant
6.
Perfume
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Perfume is a mixture of fragrant essential oils or aroma compounds, fixatives and solvents - used to give the human body, animals, food, objects, and living-spaces a pleasant scent. Ancient texts and archaeological excavations show the use of perfumes in some of the earliest human civilizations, the word perfume derives from the Latin perfumare, meaning to smoke through. Perfumery, as the art of making perfumes, began in ancient Mesopotamia and Egypt, the worlds first-recorded chemist is considered a woman named Tapputi, a perfume maker mentioned in a cuneiform tablet from the 2nd millennium BC in Mesopotamia. She distilled flowers, oil, and calamus with other aromatics, then filtered, in India, perfume and perfumery existed in the Indus civilization. One of the earliest distillations of Ittar was mentioned in the Hindu Ayurvedic text Charaka Samhita and Sushruta Samhita, in 2004 –2005, archaeologists uncovered what are believed to be the worlds oldest surviving perfumes in Pyrgos, Cyprus. The perfumes date back more than 4,000 years and they were discovered in an ancient perfumery, a 4, 000-square-meter factory housing at least 60 stills, mixing bowls, funnels, and perfume bottles. In ancient times people used herbs and spices, such as almond, coriander, myrtle, conifer resin, the book also described 107 methods and recipes for perfume-making and perfume-making equipment, such as the alembic. The Persian chemist Ibn Sina introduced the process of extracting oils from flowers by means of distillation and he first experimented with the rose. Until his discovery, liquid perfumes consisted of mixtures of oil and crushed herbs or petals, rose water was more delicate, and immediately became popular. Both the raw ingredients and the technology significantly influenced western perfumery and scientific developments. The art of perfumery was known in western Europe from 1221, taking account the monks recipes of Santa Maria delle Vigne or Santa Maria Novella of Florence. In the east, the Hungarians produced in 1370 a perfume made of scented oils blended in an alcohol solution – best known as Hungary Water – at the behest of Queen Elizabeth of Hungary. The art of perfumery prospered in Renaissance Italy, and in the 16th century the personal perfumer to Catherine de Medici, Rene the Florentine and his laboratory was connected with her apartments by a secret passageway, so that no formulae could be stolen en route. Thanks to Rene, France quickly became one of the European centers of perfume, cultivation of flowers for their perfume essence, which had begun in the 14th century, grew into a major industry in the south of France. Between the 16th and 17th centuries, perfumes were used primarily by the wealthy to mask body odors resulting from infrequent bathing, partly due to this patronage, the perfume industry developed. In 1693, Italian barber Giovanni Paolo Feminis created a perfume water called Aqua Admirabilis, today best known as eau de cologne, by the 18th century the Grasse region of France, Sicily, and Calabria were growing aromatic plants to provide the growing perfume industry with raw materials. Even today, Italy and France remain the center of European perfume design, Perfume types reflect the concentration of aromatic compounds in a solvent, which in fine fragrance is typically ethanol or a mix of water and ethanol. Various sources differ considerably in the definitions of perfume types, the intensity and longevity of a perfume is based on the concentration, intensity and longevity of the aromatic compounds, or perfume oils, used
7.
Insect
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Insects are a class of hexapod invertebrates within the arthropod phylum that have a chitinous exoskeleton, a three-part body, three pairs of jointed legs, compound eyes and one pair of antennae. They are the most diverse group of animals on the planet, including more than a million described species, the number of extant species is estimated at between six and ten million, and potentially represent over 90% of the differing animal life forms on Earth. Insects may be found in all environments, although only a small number of species reside in the oceans. The life cycles of insects vary but most hatch from eggs, insect growth is constrained by the inelastic exoskeleton and development involves a series of molts. The immature stages can differ from the adults in structure, habit and habitat, Insects that undergo 3-stage metamorphosis lack a pupal stage and adults develop through a series of nymphal stages. The higher level relationship of the Hexapoda is unclear, fossilized insects of enormous size have been found from the Paleozoic Era, including giant dragonflies with wingspans of 55 to 70 cm. The most diverse insect groups appear to have coevolved with flowering plants, adult insects typically move about by walking, flying or sometimes swimming. As it allows for rapid yet stable movement, many insects adopt a tripedal gait in which they walk with their legs touching the ground in alternating triangles, Insects are the only invertebrates to have evolved flight. Many insects spend at least part of their lives under water, with adaptations that include gills. Some species, such as water striders, are capable of walking on the surface of water, Insects are mostly solitary, but some, such as certain bees, ants and termites, are social and live in large, well-organized colonies. Some insects, such as earwigs, show maternal care, guarding their eggs, Insects can communicate with each other in a variety of ways. Male moths can sense the pheromones of female moths over great distances, other species communicate with sounds, crickets stridulate, or rub their wings together, to attract a mate and repel other males. Lampyridae in the beetle order communicate with light, humans regard certain insects as pests, and attempt to control them using insecticides and a host of other techniques. Some insects damage crops by feeding on sap, leaves or fruits, a few parasitic species are pathogenic. Some insects perform complex ecological roles, blow-flies, for example, help consume carrion, Many other insects are considered ecologically beneficial as predators and a few provide direct economic benefit. Silkworms and bees have been used extensively by humans for the production of silk and honey, in some cultures, people eat the larvae or adults of certain insects. Insect first appears documented in English in 1601 in Hollands translation of Pliny, translations of Aristotles term also form the usual word for insect in Welsh, Serbo-Croatian, Russian, etc. The evolutionary relationship of insects to other animal groups remains unclear, in the Pancrustacea theory, insects, together with Entognatha, Remipedia, and Cephalocarida, make up a natural clade labeled Miracrustacea
8.
Pheromone
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A pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the individual to impact the behavior of the receiving individuals. There are alarm pheromones, food trail pheromones, sex pheromones, Pheromones are used from basic unicellular prokaryotes to complex multicellular eukaryotes. Their use among insects has been well documented. In addition, some vertebrates, plants and ciliates communicate by using pheromones, the portmanteau word pheromone was coined by Peter Karlson and Martin Lüscher in 1959, based on the Greek φερω pheroo and ὁρμων hormon. Pheromones are also classified as ecto-hormones. For this reason, bacteria are too small to use pheromones as sex attractants on an individual basis, however, they do use them to determine the local population density of similar organisms and control behaviors that take more time to execute. Aggregation pheromones function in mate selection, overcoming host resistance by mass attack, a group of individuals at one location is referred to as an aggregation, whether consisting of one sex or both sexes. Most sex pheromones are produced by the females, only a percentage of sex attractants are produced by males. Aggregation pheromones have been found in members of the Coleoptera, Diptera, Hemiptera, Dictyoptera, aggregation pheromones are among the most ecologically selective pest suppression methods. They are nontoxic and effective at low concentrations. Some species release a volatile substance when attacked by a predator that can trigger flight or aggression in members of the same species, for example, Vespula squamosa use alarm pheromones to alert others to a threat. In Polistes exclamans, alarm pheromones are used as an alert to incoming predators. Pheromones also exist in plants, Certain plants emit alarm pheromones when grazed upon and these tannins make the plants less appetizing for the herbivore. Epideictic pheromones are different from territory pheromones, when it comes to insects, releaser pheromones are pheromones that cause an alteration in the behavior of the recipient. For example, some organisms use powerful attractant molecules to attract mates from a distance of two miles or more, in general, this type of pheromone elicits a rapid response, but is quickly degraded. In contrast, a primer pheromone has an onset and a longer duration. For example, rabbit release mammary pheromones that trigger immediate nursing behavior by their babies, signal pheromones cause short-term changes, such as the neurotransmitter release that activates a response
9.
Jmol
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Jmol is computer software for molecular modelling chemical structures in 3-dimensions. Jmol returns a 3D representation of a molecule that may be used as a teaching tool and it is written in the programming language Java, so it can run on the operating systems Windows, macOS, Linux, and Unix, if Java is installed. It is free and open-source software released under a GNU Lesser General Public License version 2.0, a standalone application and a software development kit exist that can be integrated into other Java applications, such as Bioclipse and Taverna. A popular feature is an applet that can be integrated into web pages to display molecules in a variety of ways, for example, molecules can be displayed as ball-and-stick models, space-filling models, ribbon diagrams, etc. Jmol supports a range of chemical file formats, including Protein Data Bank, Crystallographic Information File, MDL Molfile. There is also a JavaScript-only version, JSmol, that can be used on computers with no Java, the Jmol applet, among other abilities, offers an alternative to the Chime plug-in, which is no longer under active development. While Jmol has many features that Chime lacks, it does not claim to reproduce all Chime functions, most notably, Chime requires plug-in installation and Internet Explorer 6.0 or Firefox 2.0 on Microsoft Windows, or Netscape Communicator 4.8 on Mac OS9. Jmol requires Java installation and operates on a variety of platforms. For example, Jmol is fully functional in Mozilla Firefox, Internet Explorer, Opera, Google Chrome, fast and Scriptable Molecular Graphics in Web Browsers without Java3D
10.
Aroma compound
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An aroma-compound, also known as an odorant, aroma, fragrance, or flavor, is a chemical compound that has a smell or odor. A chemical-compound has a smell or odor when it is volatile to be transported to the olfactory system in the upper-part of the nose. Generally molecules meeting this specification have molecular weights of <300, flavors affect both the sense of taste and smell, whereas fragrances affect only smell. Flavors tend to be occurring, and fragrances tend to be synthetic. Aroma-compounds can be found in food, wine, spices, floral scent, perfumes, fragrance oils, for example, many form biochemically during the ripening of fruits and other crops. In wines, most form as byproducts of fermentation, an odorizer may add an odorant to a dangerous odorless substance, like propane, natural gas, or hydrogen, as a safety measure. Note, Carvone, depending on its chirality, offers two different smells, furaneol 1-Hexanol cis-3-Hexen-1-ol Menthol High concentrations of aldehydes tend to be very pungent and overwhelming, but low concentrations can evoke a wide range of aromas. Acetaldehyde Hexanal cis-3-Hexenal Furfural Hexyl cinnamaldehyde Isovaleraldehyde – nutty, fruity, cocoa-like Anisic aldehyde – floral, sweet and it is a crucial component of chocolate, vanilla, strawberry, raspberry, apricot, and others. Its smell is so potent it can be detected several hundred meters downwind mere seconds after a container is opened, butane-1-thiol, commonly called normal-butyl mercaptan is a chemical-intermediate. Olfactory-receptors are cell-membrane receptors on the surface of neurons in the olfactory system that detect air-borne. In mammals, olfactory-receptors are expressed on the surface of the epithelium in the nasal cavity. In 2005–06, fragrance-mix was the third-most-prevalent allergen in patch tests, Fragrance was voted Allergen of the Year in 2007 by the American Contact Dermatitis Society. The composition of fragrances is usually not disclosed in the label of products, hiding the actual chemicals of the formula, the EPA, however, does not conduct independent-safety testing but relies on data provided by the manufacturer. In 2010 the International Fragrance Association published a list of 3,059 chemicals used in 2011 based on a voluntary-survey of its members and it was estimated to represent about 90% of the worlds production-volume of fragrances
11.
European Chemicals Agency
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ECHA is the driving force among regulatory authorities in implementing the EUs chemicals legislation. ECHA helps companies to comply with the legislation, advances the safe use of chemicals, provides information on chemicals and it is located in Helsinki, Finland. The Agency, headed by Executive Director Geert Dancet, started working on 1 June 2007, the REACH Regulation requires companies to provide information on the hazards, risks and safe use of chemical substances that they manufacture or import. Companies register this information with ECHA and it is freely available on their website. So far, thousands of the most hazardous and the most commonly used substances have been registered, the information is technical but gives detail on the impact of each chemical on people and the environment. This also gives European consumers the right to ask whether the goods they buy contain dangerous substances. The Classification, Labelling and Packaging Regulation introduces a globally harmonised system for classifying and labelling chemicals into the EU. This worldwide system makes it easier for workers and consumers to know the effects of chemicals, companies need to notify ECHA of the classification and labelling of their chemicals. So far, ECHA has received over 5 million notifications for more than 100000 substances, the information is freely available on their website. Consumers can check chemicals in the products they use, Biocidal products include, for example, insect repellents and disinfectants used in hospitals. The Biocidal Products Regulation ensures that there is information about these products so that consumers can use them safely. ECHA is responsible for implementing the regulation, the law on Prior Informed Consent sets guidelines for the export and import of hazardous chemicals. Through this mechanism, countries due to hazardous chemicals are informed in advance and have the possibility of rejecting their import. Substances that may have effects on human health and the environment are identified as Substances of Very High Concern 1. These are mainly substances which cause cancer, mutation or are toxic to reproduction as well as substances which persist in the body or the environment, other substances considered as SVHCs include, for example, endocrine disrupting chemicals. Companies manufacturing or importing articles containing these substances in a concentration above 0 and they are required to inform users about the presence of the substance and therefore how to use it safely. Consumers have the right to ask the retailer whether these substances are present in the products they buy, once a substance has been officially identified in the EU as being of very high concern, it will be added to a list. This list is available on ECHA’s website and shows consumers and industry which chemicals are identified as SVHCs, Substances placed on the Candidate List can then move to another list
12.
Odor
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An odor or odour or fragrance is caused by one or more volatilized chemical compounds, generally at a very low concentration, that humans or other animals perceive by the sense of olfaction. Odors are also commonly called scents, which can refer to both pleasant and unpleasant odors, the terms fragrance and aroma are used primarily by the food and cosmetic industry to describe a pleasant odor, and are sometimes used to refer to perfumes, and to describe floral scent. In contrast, malodor, stench, reek, and stink are used specifically to describe unpleasant odor, the term smell is used for both pleasant and unpleasant odors. In the United Kingdom, odour refers to scents in general, the sense of smell gives rise to the perception of odors, mediated by the olfactory nerve. The olfactory receptor cells are present in the olfactory epithelium. There are millions of olfactory receptor neurons that act as sensory signaling cells, each neuron has cilia in direct contact with air. The olfactory nerve is considered the smell mediator, the axon connects the brain to the external air, odorous molecules act as a chemical stimulus. Molecules bind to receptor proteins extended from cilia, initiating an electric signal, thus, by using a chemical that binds to copper in the mouse nose, so that copper wasn’t available to the receptors, the authors showed that the mice couldnt detect the thiols. However, these also found that MOR244-3 lacks the specific metal ion binding site suggested by Suslick. When the signal reaches a threshold, the fires, sending a signal traveling along the axon to the olfactory bulb. Interpretation of the begins, relating the smell to past experiences. The olfactory bulb acts as a station connecting the nose to the olfactory cortex in the brain. Olfactory information is processed and projected through a pathway to the central nervous system. Odor sensation usually depends on the concentration available to the olfactory receptors, the olfactory system does not interpret a single compound, but instead the whole odorous mix, not necessarily corresponding to concentration or intensity of any single constituent. The widest range of odors consists of compounds, although some simple compounds not containing carbon, such as hydrogen sulfide. The perception of an effect is a two-step process. First, there is the part, the detection of stimuli by receptors in the nose. The stimuli are processed by the region of the brain which is responsible for olfaction
