respiration

Question 1

glycolysis

Answer 1

• Substrate level phosphorylation-2 ATP molecules add 2 phosphate groups to glucose
• glucose phosphate splits into two triose phosphate (3C) molecules
• both TP molecules are oxidised (reducing NAD) to form 2 pyruvate molecules (3C)
• releases 4 ATP molecules

Question 2

link reaction

Answer 2

• Reduced NAD and pyruvate are actively transported to matrix
• pyruvate is oxidised to acetate (forming reduced NAD)
• carbon removed and CO2 forms
• acetate combines with coenzyme A to form acetylcoenzyme A (2C)

Question 3

Krebs cycle

Answer 3

• Acetylcoenzyme A combines with 4C molecule to produce a 6C molecule - enters cycle
• oxidation-reduction reactions

Question 4

electron transfer chain

Answer 4

• The electrons pass along the chain of carrier molecules, in a series of
  oxidation-reduction reactions
• As they move, energy is released
• This energy causes active transport of protons (H+) across the membrane into the mitochondrial inner membrane space
• This creates a chemiosmotic gradient
• As the protons diffuse through ATP is created from ADP and Pi
• The protons combine with the electrons and also oxygen to form water
• Oxygen is the final electron acceptor