"Amino Acids"

Amino acids are the building blocks of proteins and play crucial roles in various biological processes. They contain an amino group (-NH₂), a carboxyl group (-COOH), a hydrogen atom, and a unique side chain (R group) attached to a central carbon (α-carbon).

Types of Amino Acids

There are 20 standard amino acids, classified into different categories based on their properties and nutritional importance.

1. Essential vs. Non-Essential Amino Acids

• Essential amino acids: Cannot be synthesized by the body and must be obtained from food.
• Examples: Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine
• Non-essential amino acids: Can be synthesized by the body.
• Examples: Alanine, Asparagine, Aspartic acid, Glutamic acid

2. Conditional Amino Acids

• Normally non-essential but may become essential during stress or illness.
• Examples: Arginine, Cysteine, Glutamine, Tyrosine, Glycine, Proline, Serine

3. Classification Based on Side Chain Properties

• Non-polar (hydrophobic) amino acids: Have hydrophobic side chains.
• Examples: Glycine, Alanine, Valine, Leucine, Isoleucine, Methionine, Phenylalanine, Tryptophan, Proline
• Polar (hydrophilic) amino acids: Have side chains that interact with water.
• Examples: Serine, Threonine, Cysteine, Tyrosine, Asparagine, Glutamine
• Charged amino acids:
• Acidic (negatively charged): Aspartic acid, Glutamic acid
• Basic (positively charged): Lysine, Arginine, Histidine

Functions of Amino Acids

• Protein synthesis: Essential for building muscle, enzymes, and structural proteins.
• Metabolism: Act as precursors for neurotransmitters, hormones, and other biomolecules.
• Immune function: Some amino acids like glutamine support the immune system.
• Energy production: Can be used as an energy source during starvation or intense exercise.