Carbon Based Molecules

Hook Question

  • What major molecules are living things made up of?

Carbon Based Molecules (Biomolecules)

  • Important concept in biology for Grade 9.

Elements in Living Things

  • 95% of living organism’s mass consists of the following elements:

    • C = Carbon

    • H = Hydrogen

    • N = Nitrogen

    • O = Oxygen

    • P = Phosphorus

    • S = Sulfur

  • Questions to consider:

    1. Which element is the most abundant?

    2. Can you think of examples of molecules/compounds that are made of that element?

Why is Carbon Important?

  • Carbon is the fundamental building block of life.

  • Can form up to 4 bonds with itself or other atoms, providing diverse structures:

    • Straight chains

    • Branched chains

    • Ring structures

  • Carbon-carbon bonds are extremely strong and stable.

Carbon Based Molecules

  • Most of the body’s mass, not including water, is composed of organic compounds.

  • Organic Compounds: Contains carbon and hydrogen (hydrocarbons).

  • Inorganic Compounds: Do not contain carbon, e.g., CO2, H2O, NaCl.

Macromolecules

  • Biological molecules are often large constructs from smaller subunits.

  • Many carbon-based molecules form large structures known as Macromolecules.

Monomer vs. Polymer

  • Biological Macromolecules: Large molecules essential for life, also called polymers.

    • Monomers: Single subunits in larger molecules.

      • "MONO" = ONE, "MER" = molecule.

    • Polymers: Large molecules made of many monomers bonded together.

      • "POLY" = MANY.

Macromolecules of Life

  • The major types of biomolecules include:

    • Carbohydrates

    • Lipids (Fats)

    • Proteins

    • Nucleic Acids (DNA)

Carbohydrates (Saccharides)

  • Elements: Carbon, Hydrogen, Oxygen (1:2:1 ratio, twice as many H to C or O).

  • Biological Functions:

    • Provide fast energy and short-term energy storage.

    • Structural support in plant cell walls.

Structure and Function of Carbohydrates

  • Monomer: Monosaccharide (single sugar).

  • Polymer: Polysaccharide (chain of sugars).

  • Biological Functions:

    • Simple sugars provide fast energy.

    • Complex sugars serve as slow energy sources.

Types of Sugars

  • Simple Sugars (Monosaccharides):

    • Example: Glucose (primary energy source in cells).

    • Disaccharides: Two monosaccharides (e.g., sucrose, lactose).

  • Complex Sugars (Polysaccharides):

    • Examples:

      • Starch (plants store food as starch).

      • Glycogen (energy storage in liver and muscles).

      • Cellulose (provides structural support in plants).

Lipids

  • Elements: Carbon, Hydrogen, Oxygen.

  • Biological Functions:

    • Nonpolar (not soluble in water).

    • Insulation and waterproofing.

    • Long-term energy storage.

    • Structural component of cell membranes.

  • Examples: Fats, phospholipids, waxes, oils, steroids.

  • Types of Fats:

    • Saturated (solid at room temperature, e.g., butter).

    • Unsaturated (liquid at room temperature, e.g., olive oil).

Lipid Structure

  • Monomers: Fatty acids + Glycerol.

  • Functions:

    • Energy storage.

    • Insulation.

    • Cellular structure (membranes and waterproofing).

    • Hormonal functions.

Fatty Acids

  • Chains of carbon bonded to hydrogen.

  • Saturated Fats: Max number of hydrogen atoms (single bonds only).

  • Unsaturated Fats: Fewer hydrogen atoms (double bonds present).

Proteins

  • Elements: Carbon, Hydrogen, Oxygen, Nitrogen (some proteins may include Sulfur).

  • Biological Functions:

    • Catalyze chemical reactions (as enzymes).

    • Provide structural support.

    • Transport different molecules within cells.

    • Serve protective roles (antibodies).

  • Examples: Enzymes, Collagen, Keratin, Hemoglobin, Antibodies.

Protein Structure and Function

  • Building Blocks: Amino acids (20 different types).

  • Structure determines function; sequences affect properties and roles.

  • Functions include:

    • Structural (hair and nails).

    • Transport (hemoglobin).

    • Movement (muscle proteins).

    • Defense (antibodies).

    • Regulation (hormonal/enzymatic).

Nucleic Acids

  • Elements: Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus.

  • Biological Function:

    • Store and transmit genetic information.

  • Examples:

    • DNA: Two-stranded, contains genetic code.

    • RNA: Single-stranded, copy and transfer genetic information for protein synthesis.

  • Monomer: Nucleotide (composed of a sugar, base, and phosphate group).