3.5.2 Respiration

• In aerobic respiration, 1 glucose molecule converted into 38 ATP molecules. In anaerobic respiration 1 glucose molecule is converted into 2 ATP molecules.
• Aerobic respiration formula:

  Glucose + oxygen -> Carbon dioxide + water + ATP
• Anaerobic respiration formula:

  In animals- Glucose + oxygen -> Lactic acid + ATP

  In plants- Glucose + oxygen -> Ethanol + Carbon dioxide + ATP
• Cellular functions of ATP:

  • Muscle contraction
  • Protein synthesis
  • Phosphorylation reactions- makes receiving molecules more reactive
• 4 processes in aerobic respiration:

  1. Glycolysis
  2. Link reaction
  3. Krebs cycle
  4. Oxidative phosphorylation
• Glycolysis- 3 step process which occurs within the cytoplasm

  1. Glucose is phosphorylated using 2 ATP molecules, which produces glucose 1,6 phosphate.
  2. Glucose 1,6 phosphate is split into 2 molecules of triose phosphate .
  3. 2 molecules of triose phosphate are oxidised into 2 molecules of pyruvate, by reducing NAD into NADH and using 2 ADP molecules which produces 2 molecules of ATP.
• Link reaction- 2 step process which occurs within the mitochondrial matrix, where pyruvate crosses the inner and outer mitochondrial membranes, requiring 2 transport proteins.

  1. Pyruvate is oxidised into acetate, by reducing NAD into NADH, also producing CO2 via decarboxylation.
  2. Pyruvate