Protein carbohydrate degradation

The nutritional consequences of an excess protein diet are the same as those of an excess carbohydrate or excess fat diet lipid biosynthesis and fat deposition. Additionally, the protein amino groups must be detoxified and eliminated. The nutritional consequences of a diet lacking complete protein—that is, one that doesn t supply the essential amino acids in the proportions needed for synthesis of proteins and neurotransmitters—also include excess ammonia generation. In this case, muscle proteins are degraded to supply enough of the limiting essential amino acid. The other amino acids are broken down, with the carbon chains metabolized into carbohydrates (and, potentially lipid). The leftover amino groups must then be eliminated as urea. 

Alcohol is distilled up to a content of 96% in one or more stages. About 1 % of ethanol consists of fusel oils (degradation products of amino acids) which can be used as solvents for lacquers and resins. Solids from the processed liquor containing proteins, carbohydrates, mineral salts, riboflavin and other vitamins are used in poultry, swine and cattle feeds. C02 and H2 produced in butanol-acetone-butyric acid production can be used for the chemical synthesis of methanol and ammonia, or are burned. 

Tissues carry out an enormous number of chemical reactions. Collectively these are referred to as metabolism. Some reactions or reaction sequences (often referred to as metabolic pathways) create complex molecules from simpler molecules, and these processes are then called anabolism. Many reactions, however, serve to break down complex molecules into simple molecules, and these processes are called catabolism. Among the latter is the degradation of foodstuffs, such as proteins, carbohydrates, and fats. Often these are degraded to C02 and HzO, which are excreted by the organism. The purpose of doing this is to acquire useful energy, which is in turn required for the various life processes, including... 

Organic matter deposited in sedimentary or wetland habitats is composed of a complex mixture of biopolymers. Some of these compounds, such as proteins, carbohydrates, and lipids are easily degraded by microorganisms (i.e., labile), while other compounds, such as lignin and hemiceUulose, are resistant to decomposition (i.e., recalcitrant). Biopolymers are degraded in a multistep process. First, microorganisms simplify polymers to monomers such as amino acids, fatty acids, and monosaccharides (Figure 4). The monomers are further mineralized to CO2, or to a combination of CO2 and CH4. 

Protects the protein from degradation by proteases and masks the carbohydrate receptor clearance mechanisms. 

Another area of considerable conceptual difficulty relates to the observation that the adult animal exists in a more-or-less steady-state, well removed from equilibrium. When observed day-to-day there is generally little variation in body composition while the animal is on a consistent diet, the mass of protein, carbohydrate, and fat remaining approximately constant. This constancy is maintained despite the rapid turnover of the body s constituents. The living system is not static but dynamic, the steady-state being maintained because synthetic reactions exactly balance degradative processes. How this balance is achieved and what governs the overall rate of metabolic flux and heat production are the main topics of this section. 

W. is a reactant in enzyme (hydrolase)-catalysed hydrolytic cleavage of macromolecules (proteins, carbohydrates, fats), representing the first stage in the biological degradation of these substances. W. is formed metabolically by the operation of the respiratory chain (Thble 3) (respiratory W.), and is the substrate of photosynthesis. 

Yet another important outcome of the CAZy classification scheme is the recognition that many carbohydrate-degrading enzymes are multimodular, consisting of a single polypeptide chain with independently folding structural elements fulfilling diverse roles. Examples of such modules include catalytic, structural, protein-protein interaction, and carbohydrate-binding modules, which may be connected with defined linker sequences (28,34). Consideration of carbohydrase modularity is thus essential to fully understand the catalytic function of these proteins. 

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