Carbon Structures in Molecules

• Diversity in carbon chains: linear, ring, fused ring (e.g., cholesterol)
• Types of bonds: single vs double bonds
• Presence of functional groups

Nucleic Acids

• Composed of nucleotides
• Parts of nucleotides:
  • Phosphate group
  • Pentose sugar
  • Nitrogen-containing base

Lipids

• Triglycerides:
  • Unsaturated fats are liquid at room temperature
  • Saturated fats are solid at room temperature
• Example of fatty types in organisms:
  • Mammals can have saturated fats due to temperature regulation
  • Plants typically have unsaturated fats (e.g., olive, corn oil)
  • Tropical plants can have saturated fats (e.g., coconut oil)

Phospholipids

• Amphipathic nature:
  • Polar heads, nonpolar fatty acid tails
• Essential for membrane structure

Proteins

• Made of 20 different amino acids
• Structure of amino acids:
  • Central carbon, carboxyl group, amino group, hydrogen, variable R group
• Classification of amino acids:
  • Nonpolar (hydrophobic)
  • Polar uncharged
  • Charged (ionic bonds)

Peptide Bonds and Protein Structure

• Peptides form through dehydration synthesis
• Defined by N-terminus and C-terminus
• Levels of protein structure:
  1. Primary: sequence of amino acids
  2. Secondary: localized folding (alpha helix, beta sheets)
  3. Tertiary: overall 3D shape based on side chains
  4. Quaternary: multiple polypeptide chains

Functionality of Proteins

• Importance of conformational shape for function
• Factors stabilizing structure:
  • Covalent bonds (disulfide bridges)
  • Ionic bonds
  • Hydrogen bonds
  • Hydrophobic interactions

Interactions and Denaturation

• Heat disrupts hydrogen bonds, denaturing proteins
• Proteins can regain structure unless fully denatured by moisture

Concept Mapping

• A strategy to connect and understand relationships between macromolecules (carbohydrates, proteins, lipids, nucleic acids)
• Useful for revision and exams