Metabolism is the set of life-sustaining chemical reactions in organisms. The three main purposes of metabolism are: the conversion of food to energy to run cellular processes; these enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their structures, respond to their environments.. Metabolic reactions may be categorized as catabolic - the breaking down of compounds. Catabolism releases energy, anabolism consumes energy; the chemical reactions of metabolism are organized into metabolic pathways, in which one chemical is transformed through a series of steps into another chemical, each step being facilitated by a specific enzyme. Enzymes are crucial to metabolism because they allow organisms to drive desirable reactions that require energy that will not occur by themselves, by coupling them to spontaneous reactions that release energy. Enzymes act as catalysts - they allow a reaction to proceed more - and they allow the regulation of the rate of a metabolic reaction, for example in response to changes in the cell's environment or to signals from other cells.
The metabolic system of a particular organism determines which substances it will find nutritious and which poisonous. For example, some prokaryotes use hydrogen sulfide as a nutrient, yet this gas is poisonous to animals; the basal metabolic rate of an organism is the measure of the amount of energy consumed by all of these chemical reactions. A striking feature of metabolism is the similarity of the basic metabolic pathways among vastly different species. For example, the set of carboxylic acids that are best known as the intermediates in the citric acid cycle are present in all known organisms, being found in species as diverse as the unicellular bacterium Escherichia coli and huge multicellular organisms like elephants; these similarities in metabolic pathways are due to their early appearance in evolutionary history, their retention because of their efficacy. Most of the structures that make up animals and microbes are made from three basic classes of molecule: amino acids and lipids; as these molecules are vital for life, metabolic reactions either focus on making these molecules during the construction of cells and tissues, or by breaking them down and using them as a source of energy, by their digestion.
These biochemicals can be joined together to make polymers such as DNA and proteins, essential macromolecules of life. Proteins are made of amino acids arranged in a linear chain joined together by peptide bonds. Many proteins are enzymes. Other proteins have structural or mechanical functions, such as those that form the cytoskeleton, a system of scaffolding that maintains the cell shape. Proteins are important in cell signaling, immune responses, cell adhesion, active transport across membranes, the cell cycle. Amino acids contribute to cellular energy metabolism by providing a carbon source for entry into the citric acid cycle when a primary source of energy, such as glucose, is scarce, or when cells undergo metabolic stress. Lipids are the most diverse group of biochemicals, their main structural uses are as part of biological membranes both internal and external, such as the cell membrane, or as a source of energy. Lipids are defined as hydrophobic or amphipathic biological molecules but will dissolve in organic solvents such as alcohol, benzene or chloroform.
The fats are a large group of compounds that contain fatty glycerol. Several variations on this basic structure exist, including alternate backbones such as sphingosine in the sphingolipids, hydrophilic groups such as phosphate as in phospholipids. Steroids such as cholesterol are another major class of lipids. Carbohydrates are aldehydes or ketones, with many hydroxyl groups attached, that can exist as straight chains or rings. Carbohydrates are the most abundant biological molecules, fill numerous roles, such as the storage and transport of energy and structural components; the basic carbohydrate units are called monosaccharides and include galactose and most glucose. Monosaccharides can be linked together to form polysaccharides in limitless ways; the two nucleic acids, DNA and RNA, are polymers of nucleotides. Each nucleotide is composed of a phosphate attached to a ribose or deoxyribose sugar group, attached to a nitrogenous base. Nucleic acids are critical for the storage and use of genetic information, its interpretation through the processes of transcription and protein biosynthesis.
This information is propagated through DNA replication. Many viruses have an RNA genome, such as HIV, which uses reverse transcription to create a DNA template from its viral RNA genome. RNA in ribozymes such as spliceosomes and ribosomes is similar to enzymes as it can catalyze chemical reactions. Individual nucleosides
Cvijetin Blagojević is a Bosnian Serb football manager and former player. Born in Lopare, during his playing career he played in the Yugoslav First League clubs FK Sloboda Tuzla and Red Star Belgrade before deciding to continue his career abroad, playing first in Greece with Egaleo F. C. and with Swedish club Vasalunds IF, Portuguese CS Marítimo. After retiring, he became a football manager, he coached Šumarice and Plavi tim in Sweden, returned to the region of former-Yugoslavia where he coached Železnik, Kozara Gradiška, Radnički Obrenovac, Red Star Belgrade youth team, Radnički Pirot, Radnik Surdulica and Drina Zvornik. Na današnji dan rođen Cvijetin Blagojević at mojacrvenazvezda.net Cvijetin Blagojević at WorldFootball.net Cvijetin Blagojević at ForaDeJogo
The Tulsa Golden Hurricane football statistical leaders are individual statistical leaders of the Tulsa Golden Hurricane football program in various categories, including passing, receiving, total offense, defensive stats, kicking. Within those areas, the lists identify single-game, single-season, career leaders; the Golden Hurricane represent the University of Tulsa in the NCAA's American Athletic Conference. Although Tulsa began competing in intercollegiate football in 1895, the school's official record book considers the "modern era" to have begun in 1941. Records from before this year are incomplete and inconsistent, they are not included in these lists; these lists are dominated by more recent players for several reasons: Since 1941, seasons have increased from 10 games to 11 and 12 games in length. The NCAA didn't allow freshmen to play varsity football until 1972, allowing players to have four-year careers. Bowl games only began counting toward single-season and career statistics in 2002.
The Golden Hurricane have played in 10 bowl games since this decision, giving many recent players an extra game to accumulate statistics. However, the passing and receiving lists see many entries during the 1961-1968 tenure of head coach Glenn Dobbs, whose teams led the NCAA in passing yards five times in an era before today's modern spread offenses; these lists are updated through the end of the 2016 season. Note that the Tulsa official record book does not include any information for some of these statistics. Total offense is the sum of rushing statistics, it does not include receiving or returns