Amino Acid

Amino acids are essential organic molecules that serve as the primary structural units of proteins and play vital roles in numerous biological processes. These remarkable compounds derive their name from their dual chemical nature, containing both an amino group (-NH₂) and a carboxylic acid group (-COOH).

Chemical Structure

The basic structure of an amino acid consists of:

• A central carbon atom (α-carbon)
• An amino group (-NH₂)
• A carboxylic acid group (-COOH)
• A unique side chain (R-group)
• A hydrogen atom

This arrangement creates a chirality in most amino acids, leading to distinct three-dimensional configurations.

Classification

Essential vs. Non-essential

• Essential amino acids: Cannot be synthesized by the human body (must be obtained through diet)
• Non-essential amino acids: Can be synthesized internally through metabolism

Chemical Properties

1. Polar: Water-soluble side chains
2. Non-polar: Hydrophobic side chains
3. Acidic: Negative charge at physiological pH
4. Basic: Positive charge at physiological pH

Biological Functions

Amino acids serve multiple crucial roles:

1. Protein Synthesis

   • Form peptide bonds to create protein structures
   • Enable proper protein folding

2. Metabolic Functions

   • Energy production
   • Neurotransmitter synthesis
   • Hormone production

3. Physiological Roles

   • pH regulation
   • Immune system support
   • Cell signaling

The 20 Standard Amino Acids

The genetic code specifies 20 standard amino acids, each with unique properties:

1. Hydrophobic (e.g., leucine, isoleucine)
2. Polar (e.g., serine, threonine)
3. Charged (e.g., lysine, glutamic acid)
4. Special cases (e.g., proline, glycine)

Medical and Industrial Applications

Amino acids have numerous applications in:

• Pharmaceutical development
• Sports nutrition
• Food industry
• Biotechnology research

Disorders and Deficiencies

Several medical conditions relate to amino acid metabolism:

• Phenylketonuria
• Maple syrup urine disease
• Various genetic disorders affecting amino acid processing

Understanding amino acids is fundamental to biochemistry and forms the basis for many areas of biological research and medical treatment. Their role in protein structure and function makes them central to life processes and modern biotechnology applications.