3.2 Biomolecules

Carbohydrates

• Monosaccharides: Simple sugars (Glucose, Ribose, Deoxyribose).
• Disaccharides: Two monosaccharides linked by a glycosidic bond (Maltose, Lactose, Sucrose).
• Polysaccharides: Long chains of monosaccharides (Glycogen, Starch, Cellulose, Chitin).

Proteins

• Amino Acids: Building blocks of proteins, with an amino group, a carboxyl group, and an R group.
• Levels of Protein Structure:
  • Primary: Linear sequence of amino acids.
  • Secondary: α-helix and β-pleated sheet.
  • Tertiary: 3D shape of a single polypeptide.
  • Quaternary: Arrangement of multiple polypeptide subunits.

Lipids

• Fats and Oils (Triglycerides): Glycerol + 3 Fatty Acids.
• Functions:
  • Energy storage.
  • Insulation.
  • Protection.
  • Absorption of fat-soluble vitamins.

Enzymes

• Definition: Biological catalysts (mostly proteins) that speed up reactions.
• Properties: Highly specific, work at optimal pH and temperature.
• Classification (6 Classes): Oxidoreductases, Transferases, Hydrolases, Lyases, Isomerases, Ligases.
• Factors Affecting Activity: Temperature, pH, substrate concentration.

Enzyme Inhibition

• Competitive Inhibition:
  • An inhibitor molecule competes with the substrate for the active site.
  • The inhibitor has a structure similar to the substrate.

Secondary Metabolites

• Definition: Compounds not directly involved in the normal growth, development, or reproduction of an organism.
• Examples:
  • Alkaloids: Morphine, Codeine
  • Terpenoids: Menthol
  • Toxins: Ricin
  • Drugs: Vinblastin
  • Polymers: Rubber, Gums