Final answer:
Hepatic oxidation, transamination, deamination, and bacterial breakdown in the gut lead to the metabolism of amino acids, resulting in various metabolites such as urea, uric acid, CO₂, and keto acids. This process involves the liver and several other tissues, producing energy and assisting in the excretion of nitrogenous wastes.
Step-by-step explanation:
Metabolism of Amino Acids
Hepatic oxidation, transamination, deamination, and bacterial breakdown in the gut lead to the conversion of amino acids into various metabolites. The process includes oxidative deamination, in which an amino group is removed following oxidation. Enzymes such as amino acid oxidase, requiring coenzymes like FMN and FAD, facilitate the reaction where amino acids are converted to keto acids, releasing ammonium ions. The reduced coenzymes FMNH₂ and FADH₂ are directly reoxidized by oxygen in this process.
Transamination involves the transfer of an amino group to a keto acid, typically alpha-ketoglutarate, resulting in the formation of glutamate. Glutamate is then able to undergo oxidative deamination, generating ammonium ions and converting back to alpha-ketoglutarate. During amino acid catabolism, the carbon skeletons are directed to various metabolic pathways; they can become sources for glucose or fat synthesis, contribute to the citric acid cycle, or contribute to other metabolites such as urea, uric acid, and more.
The liver is a central site for these processes, but other tissues such as the kidney and muscles also participate. Through these enzymatic reactions, amino acids can be used for energy production, synthesis of new compounds, or clearance of excess nitrogen through the urea cycle.