3.5.2.3 - Anaerobic Respiration

Question 1

Why does the electron transport chain, krebs cycle and link reaction stop in the absence of oxygen?

Answer 1

Oxygen is the final electron acceptor in the ETC.

Electrons ‘back up’ along ETC.

NADH and FADH₂ are unable to become oxidised.

NAD and FAD are not regenerated.

NAD and FAD (Krebs only) needed to oxidise substrates of Krebs and link reactions.

Question 2

Which reaciton is the only source of ATP in anaerobic conditions?

Answer 2

Glycolysis

Question 3

Can glucose cross the mitochondrial membrane?

Answer 3

No - glycolysis breaks it down into pyruvate, which is then transported across the membrane.

Question 4

What is the equation for anaerobic respiration in plants/microorganisms.

Answer 4

Pyruvate + NADH –> Ethanol + CO₂ + NAD

Question 5

Which equation is shown below:

Pyruvate + NADH –> Ethanol + CO2 + NAD

Answer 5

Anaerobic respiration in plants/bacteria

Pyruvate + NADH –> Ethanol + CO2 + NAD