alpha-amino acid metabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways involving an alpha-amino acid. [GOC:TermGenie]

Alpha-amino acid metabolism encompasses a vast and intricate network of biochemical reactions that govern the synthesis, degradation, and interconversion of alpha-amino acids, the building blocks of proteins. These processes are essential for life, playing critical roles in:

* **Protein biosynthesis:** Amino acids are the fundamental units for constructing proteins, which perform diverse functions in cells and organisms.
* **Energy production:** Certain amino acids can be catabolized to generate energy through the citric acid cycle and oxidative phosphorylation.
* **Biosynthesis of other molecules:** Amino acids serve as precursors for the synthesis of various biomolecules, including neurotransmitters, hormones, and nucleotides.

The alpha-amino acid metabolic process can be broadly divided into two major pathways:

**1. Amino acid biosynthesis:**

* **De novo synthesis:** Some amino acids can be synthesized from simpler precursors, such as carbohydrates and intermediates of the citric acid cycle. This process requires specific enzymes and cofactors and is typically regulated by feedback mechanisms to ensure an adequate supply of amino acids.
* **Transamination:** This reaction involves the transfer of an amino group from one molecule to another, often catalyzed by aminotransferases. This process is essential for interconverting different amino acids.

**2. Amino acid degradation:**

* **Transamination:** The initial step in amino acid degradation is often transamination, where the amino group is removed and transferred to a keto acid, forming a new amino acid and a keto acid.
* **Deamination:** The removal of the amino group as ammonia is catalyzed by deaminases. This process is crucial for nitrogen excretion in various organisms.
* **Carbon skeleton metabolism:** The remaining carbon skeleton of the amino acid is further metabolized through different pathways, ultimately producing energy or being used for the synthesis of other molecules.

Regulation of amino acid metabolism is tightly controlled at multiple levels, including:

* **Gene expression:** The expression of genes encoding enzymes involved in amino acid metabolism is regulated by various factors, including nutrient availability and hormonal signals.
* **Enzyme activity:** The activity of enzymes involved in amino acid metabolism can be regulated by allosteric effectors, covalent modifications, and proteolytic degradation.
* **Substrate availability:** The availability of specific amino acids can influence the activity of metabolic pathways.

Disruptions in alpha-amino acid metabolism can lead to various metabolic disorders, such as phenylketonuria, maple syrup urine disease, and alkaptonuria. These disorders are often caused by genetic defects in enzymes involved in specific amino acid metabolic pathways.

In summary, alpha-amino acid metabolism is a complex and dynamic process that is essential for life. It involves the synthesis, degradation, and interconversion of amino acids, providing building blocks for proteins, energy sources, and precursors for other biomolecules. Understanding this intricate network of biochemical reactions is crucial for understanding human health and disease.'
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Proteins (1)

Compounds (3)