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Tambayan ng mga Chicx at Tsonx => Body Talks => Topic started by: dakilang mangangalakal on May 20, 2013, 07:22:56 AM
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METABOLISM
Metabolism is what you call for the series of chemical reactions that occur within your body to sustain life. There are two types of metabolism: anabolism and catabolism.
MAIN difference between the two is that anabolism synthesizes small molecules into a complex compound while catabolism acts the other way around, it breaks complex compound into smaller molecules.
Because of such, anabolic reactions are divergent processes. The reaction would be A -> B + C + D + E. So, few raw materials are utilised to synthesize a lot of end products. Such action results in an increase in cellular size or complexity—or both.
The catabolism works in convergent process.
Catabolism is also known as a "downhill" process during which energy is released, while anabolism requires the input of energy, and is therefore an energetically "uphill" process. At certain points in the anabolic pathway, the cell must put more energy into a reaction than is released during catabolism. Such anabolic steps require a different series of reaction than are used at this point during catabolism.
Anabolism, or biosynthesis, is the process by which living organisms synthesize complex molecules of life from simpler ones. Anabolism, together with catabolism, are the two series of chemical processes in cells that are, together, called metabolism. Anabolic reactions are divergent processes. That is, relatively few types of raw materials are used to synthesize a wide variety of end products. This results in an increase in cellular size or complexity—or both.
Anabolic processes produce peptides, proteins, polysaccharides, lipids, and nucleic acids. These molecules comprise all the materials of living cells, such as membranes and chromosomes, as well as the specialized products of specific types of cells, such as enzymes, antibodies, hormones, and neurotransmitters.
Catabolism, the opposite of anabolism, produces smaller molecules used by the cell to synthesize larger molecules, as will be described below. Thus, in contrast to the divergent reactions of anabolism, catabolism is a convergent process, in which many different types of molecules are broken down into relatively few types of end products.
The energy required for anabolism is supplied by the energy-rich molecule adenosine triphosphate (ATP). This energy exists in the form of the high-energy chemical bond between the second and third molecule of phosphate on ATP. ATP's energy is released when this bond is broken, turning ATP into adenosine diphosphate (ADP). During anabolic reactions, the high-energy phosphate bond of ATP is transferred to a substrate (a molecule worked on by an enzyme) in order to energize it in preparation for the molecule's subsequent use as a raw material for the synthesis of a larger molecule. In addition to ATP, some anabolic processes also require high-energy hydrogen atoms that are supplied by the molecule NADPH.
Although anabolism and catabolism occur simultaneously in the cell, the rates of their chemical reactions are controlled independently of each other. For example, there are two enzymatic pathways for glucose metabolism. The anabolic pathway synthesizes glucose, while catabolism breaks down glucose. The two pathways share 9 of the 11 enzymatic steps of glucose metabolism, which can occur in either sequence (i.e., in the direction of anabolism or catabolism). However, two steps of glucose anabolism use an entirely different set of enzyme-catalyzed reactions.
There are two important reasons that the cell must have separate complementary anabolic and catabolic pathways. First, catabolism is a so-called "downhill" process during which energy is released, while anabolism requires the input of energy, and is therefore an energetically "uphill" process. At certain points in the anabolic pathway, the cell must put more energy into a reaction than is released during catabolism. Such anabolic steps require a different series of reaction than are used at this point during catabolism.
Second, the different pathways permit the cell to control the anabolic and catabolic pathways of specific molecules independently of each other. This is important because there are times when the cell must slow or halt a particular catabolic or anabolic pathway in order to reduce breakdown or synthesis of a particular molecule. If both anabolism and catabolism used the same pathway, the cell would not be able control the rate of either process independent of the other: slowing the rate of catabolism would slow the rate of anabolism.
Opposite anabolic and catabolic pathways can occur in different parts of the same cell. For example, in the liver the breakdown of fatty acids to the molecule acetyl-CoA takes place inside mitochondria. Mitochondria are the tiny, membrane-bound organelles that function as the cell's major site of ATP production. The buildup of fatty acids from acetyl-CoA occurs in the cytosol of the cell, that is, in the aqueous area of the cell that contains various solutes.
Although anabolic and catabolic pathways are controlled independently, both metabolic routes share an important common sequence of reactions that is known collectively as the citric acid cycle, or Krebs cycle. The Krebs cycle is part of a larger series of enzymatic reactions collectively called oxidative phosphorylation. This pathway is an important means of breaking down glucose to produce energy, which is stored in the form of ATP. But the molecules produced by the Krebs cycle can also be used as precursor molecules, or raw materials, for anabolic reactions that make proteins, fats, and carbohydrates.
Despite the independence of anabolism and catabolism, the various steps of these processes are in some ways so intimately linked that they form what might be considered an "enzymatic ecological system." In this system, a change in one part of a metabolic series of reactions can have a ripple effect throughout the linked anabolic and catabolic pathways.
Anabolism:
Anabolism (from Greek ana, "upward", and ballein, "to throw") is the set of metabolic pathways that construct molecules from smaller units.[1] These reactions require energy. One way of categorizing metabolic processes, whether at the cellular, organ or organism level is as 'anabolic' or as 'catabolic', which is the opposite. Anabolism is powered by catabolism, where large molecules are broken down into smaller parts and then used up in respiration. Many anabolic processes are powered by adenosine triphosphate (ATP).[2]
Anabolic processes tend toward "building up" organs and tissues. These processes produce growth and differentiation of cells and increase in body size, a process that involves synthesis of complex molecules. Examples of anabolic processes include the growth and mineralization of bone and increases in muscle mass.
Endocrinologists have traditionally classified hormones as anabolic or catabolic, depending on which part of metabolism they stimulate. The classic anabolic hormones are the anabolic steroids, which stimulate protein synthesis and muscle growth. The balance between anabolism and catabolism is also regulated by circadian rhythms, with processes such as glucose metabolism fluctuating to match an animal's normal periods of activity throughout the day.[3]
1. It is a constructive phase of metabolism.
2. In anabolism, complex molecules (e.g. proteins) are synthesized from simple molecules (Amino acids).
3. It is an energy (ATP) requiring process.
4. e.g. Protein synthesis, Glycogen synthesis.
Catabolism:
Catabolism (Greek kata = downward + ballein = to throw) is the set of pathways that break down molecules into smaller units and release energy.[1] In catabolism, large molecules such as polysaccharides, lipids, nucleic acids and proteins are broken down into smaller units such as monosaccharides, fatty acids, nucleotides, and amino acids, respectively. As molecules such as polysaccharides, proteins, and nucleic acids are made from long chains of these small monomer units (mono = one + mer = part), the large molecules are called polymers (poly = many).
Cells use the monomers released from breaking down polymers to either construct new polymer molecules, or degrade the monomers further to simple waste products, releasing energy. Cellular wastes include lactic acid, acetic acid, carbon dioxide, ammonia, and urea. The creation of these wastes is usually an oxidation process involving a release of chemical free energy, some of which is lost as heat, but the rest of which is used to drive the synthesis of adenosine triphosphate (ATP). This molecule acts as a way for the cell to transfer the energy released by catabolism to the energy-requiring reactions that make up anabolism. Catabolism therefore provides the chemical energy necessary for the maintenance and growth of cells. Examples of catabolic processes include glycolysis, the citric acid cycle, the breakdown of muscle protein in order to use amino acids as substrates for gluconeogenesis and breakdown of fat in adipose tissue to fatty acids.
There are many signals that control catabolism. Most of the known signals are hormones and the molecules involved in metabolism itself. Endocrinologists have traditionally classified many of the hormones as anabolic or catabolic, depending on which part of metabolism they stimulate. The so-called classic catabolic hormones known since the early 20th century are cortisol, glucagon, and adrenaline (and other catecholamines). In recent decades, many more hormones with at least some catabolic effects have been discovered, including cytokines, orexin (also known as hypocretin), and melatonin.
1. It is a destructive phase of metabolism.
2. In catabolism, complex molecules (e.g. Glycogen) are broken down into simple molecules (glucose).
3. It is an energy (ATP) releasing process.
4. E.g. Glycogenolysis, Glycolysis.
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hay.. natapos din.. ang haba.. nice read
thanks for sa share.. mahalaga talaga ang metabolism sa isang tao... dito nalalaman kung gaano ba kaeefficient ng function ng mga organ natin hehe..
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Oo ang haba. Anyway thanks for the post man.
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to help boost metabolism, take Co-Q10 50 mg tablet everyday..it helps to produce cells that boost metabolism..