Amino Acids (AA)

Amino Acids (AAs)

Definition: Amino acids (AA) are organic compounds that serve as the building blocks of proteins. They contain an amino group (-NH2), a carboxyl group (-COOH), and a unique side chain (R group) that determines the characteristics of each amino acid.

Types of Amino Acids (AA)

Amino acids can be classified into two main categories:

• Essential Amino Acids:

• These cannot be synthesized by the body and must be obtained through diet.
• Examples include:
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine
  • Isoleucine
  • Histidine

• Non-Essential Amino Acids:

• These can be synthesized by the body and do not need to be obtained from food.
• Examples include:
  • Alanine
  • Asparagine
  • Aspartic acid
  • Glutamic acid
  • Serine

Functions of Amino Acids

• Protein Synthesis: Amino acids link together via peptide bonds to form proteins, which are essential for various biological functions.
• Metabolism: They play a role in metabolic pathways, serving as precursors for hormones, neurotransmitters, and other biomolecules.
• Energy Production: Some amino acids can be converted into glucose or fatty acids to provide energy.
• Immune Function: Certain amino acids are involved in the synthesis of antibodies and other immune system components.

Clinical Relevance

• Dietary Deficiencies: Insufficient intake of essential amino acids can lead to health issues, including muscle wasting, weakened immune response, and impaired growth.
• Supplementation: Amino acid supplements are often used by athletes to enhance performance and recovery, as well as in clinical settings to support patients with specific dietary needs.
• Metabolic Disorders: Abnormalities in amino acid metabolism can lead to diseases such as phenylketonuria (PKU) and maple syrup urine disease.

Conclusion

Amino acids are fundamental to life, serving as the building blocks of proteins and playing vital roles in various physiological processes. Understanding their types, functions, and clinical significance is essential for nutrition and health.

References

1. Wu G. “Amino acids: Biochemistry and nutrition.” Amino Acids. 2009; 37(1): 1-17. DOI: 10.1007/s00726-008-0210-6
2. Holeček M. “L-Alanine metabolism in exercise.” Journal of Physiology and Pharmacology. 2005; 56(Suppl 1): 67-78.
3. Kahn SE, et al. “The role of amino acids in human nutrition.” Nutrition Reviews. 2006; 64(7): 311-318. DOI: 10.1111/j.1753-4887.2006.tb00109.x