Respiration

Question 1

Name the four main stages of aerobic respiration and where they occur

Answer 1

Glycolysis- Cytoplasm
Link reaction- Mitochondrial matrix
Krebs Cycle- Mitochondrial matrix
Oxidative Phosphorylation- electron transfer train/Intermembrane

Question 2

Outline the stages of glycolysis

Answer 2

1) Glucose is phosphorylated to glucose phosphate by 2x ATP
2) Glucose splits into 2x Triose Phosphate
3) 2x TP is oxidised into 2x Pyruvate

Net gain:

• 2x NADH
• 2x ATP

Question 3

How does pyruvate from glycolysis enter the mitochondria?

Answer 3

Via active transport

Question 4

What happens during the link reaction?

Answer 4

1) Oxidation of pyruvate to acetate
2) Each pyruvate produces 1x CO2 (via decarboxylation), 2x H atoms (via dehydrogenation) and this was used to reduce NAD
3) The acetate then combines with Coenzyme A

Question 5

What happens in the Kreb cycle?

Answer 5

A series of redox reactions that produce:

• ATP by substrate-level phosphorylation
• Reduced coenzymes
• CO2 from decarboxylation

Question 6

What is the electron transfer chain?

Answer 6

A series of carrier proteins embedded in the membrane of the cristae of mitochondria
Produces ATP through oxidative phosphorylation via chemiosmosis during aerobic respiration.