Cellular respiration

• Aerobic respiration


  1. Glycolysis

  2. Citric acid cycle & matrix of the mitochondria

  3. Electron transport chain (inner mitochondrial membrane)
• Glycolysis


  Breakdown of glucose to pyruvate
• ATP is required for the phosphorylation of glucose
• Glycolysis generates intermediates during the breakdown phase, leading to the generation of more ATP during the energy payoff stage
• Dehydrogenase


  Enzyme that reduces NAD+ to NADH
• Citric acid cycle


  1. Acetyl group from acetyl CoA combines with oxaloacetate

  2. Citrate is gradually converted back into oxaloacetate

  3. Generation of ATP and release of carbon dioxide
• Electron transport chain


  • Series of carrier proteins attached to the inner mitochondrial membrane
  • Electrons are passed along the ETC releasing energy
  • Energy used to pump hydrogen ions across the inner mitochondrial membrane
• ATP synthase


  Enzyme that uses the flow of hydrogen ions back through the membrane to produce ATP
• Hydrogen ions and electrons combine with oxygen to form water
• In the absence of oxygen


  Fermentation takes place, resulting in much less ATP being produced than in aerobic respiration
• Anaerobic respiration in animal cells


  Pyruvate is converted to lactate in a reversible reaction
• Anaerobic respiration in plant and yeast cells

  Ethanol and carbon dioxide are produced in a reversible reaction
• ATP is used to transfer energy to cellular processes which require energy