Notes on Properties and Functions of Macromolecules

Physical Science: Properties and Functions of Macromolecules

Lesson Objectives

  • Recognize and define structures of biological macromolecules and their functions.

Biomolecules

  • Definition: Large organic molecules essential for life.
  • Types of Biomolecules:
    • Carbohydrates
    • Lipids
    • Proteins
    • Nucleic Acids
  • Functions: Store energy, provide structure, and play roles in biological processes.

Monomers and Polymers

  • Monomer: A simple molecule that can bond with others to form a polymer.

Carbohydrates

  • Composition: Carbon, Hydrogen, and Oxygen (CHO).
  • Types of Carbohydrates:
    • Monosaccharides: Single sugar units (e.g., glucose, fructose).
    • Disaccharides: Two sugar units (e.g., maltose, sucrose, lactose).
    • Polysaccharides: Many sugar units (e.g., starch, glycogen, cellulose).
  • Primary Function: Main energy source for the human body.
    • Excess carbohydrates are converted to glycogen for storage in the liver and muscles.

Examples:

  • Monosaccharides:
    • Glucose: Blood sugar used by the body.
    • Fructose: Found in fruits and honey.
  • Disaccharides:
    • Maltose: Made of two glucose units.
    • Sucrose: Glucose + Fructose.
    • Lactose: Glucose + Galactose.
  • Polysaccharides:
    • Starch: Plant storage form of glucose.
    • Glycogen: Animal storage form of glucose, stored in liver/muscles.
    • Cellulose: Structural material in plant cell walls, indigestible by humans.

Lipids (Fats)

  • Composition: Made from Carbon, Hydrogen, and Oxygen.
  • Properties: Soluble in oil, insoluble in water.
  • Functions:
    • Material for cell membranes.
    • Provide insulation and aid digestion.
    • Serve as signal molecules.
  • Types of Lipids:
    • Triglycerides: Main form of fat storage.
    • Phospholipids: Important for cell membranes.
    • Steroids: Include hormones.

Examples:

  • Fats: Solid triglycerides usually from animal sources.
  • Oils: Liquid triglycerides from plant sources.

Proteins

  • Composition: Made from Carbon, Hydrogen, Oxygen, and Nitrogen (CHON).
  • Building Blocks: Amino acids, linked together by peptide bonds.
  • Functions: Structural roles, enzymes, transport, signaling.

Key Proteins:

  • Keratin: Found in hair, skin, and nails.
  • Collagen: Major protein in connective tissues, accounts for 30% of body's proteins.
  • Enzymes: Catalysts for biochemical reactions (e.g., Lipase, Pepsin, Sucrase).

Nucleic Acids

  • Composition: Made from Carbon, Hydrogen, Oxygen, Nitrogen, and Phosphorus (CHONP).
  • Function: Involves storage, transfer, and expression of genetic information.
  • Types:
    • DNA: Carries genetic code, often referred to as the blueprint of life.
    • RNA: Transfers information from DNA to the cellular machinery for protein synthesis.

Structure:

  • Monomer: Nucleotide.
  • Components: Nitrogen base, phosphate group, and a sugar molecule.

Summary of Functions of Macromolecules

  • Carbohydrates: Main energy source; glycogen is stored energy.
  • Lipids: Long-term energy storage; insulation; cell membrane structure.
  • Proteins: Diverse functions including structure, catalysis, and transport.
  • Nucleic Acids: Essential for genetic information storage and transfer.

Additional Information

  • Carbo-loading: Athletes consume high amounts of carbohydrates before events to store energy.
  • Consider dietary needs when planning meals to include appropriate macronutrients.

Written Task (for Practical Application)

  • Create a 3-day healthy meal plan for a teenager that balances carbohydrates, proteins, and lipids.