Oxidative phosphorylationAQA A-Level Biology: Mind map

Exam questions on Oxidative phosphorylation

1. Mitochondria were isolated from heart muscle and the processes taking place at their inner membranes were investigated.
   Describe the role of reduced NAD in oxidative phosphorylation.2 marks
2. In respiring mitochondria the intermembrane space is found to be more acidic than the matrix.
   Explain why the intermembrane space is more acidic than the matrix in respiring mitochondria.2 marks
3. Two inhibitors are added, separately, to suspensions of respiring mitochondria that are supplied with reduced NAD and oxygen. Inhibitor X blocks the channel in ATP synthase so that protons cannot pass through it. Inhibitor Y blocks the last carrier of the electron transfer chain so that electrons cannot be passed to oxygen.
   Predict the effects of inhibitor X on ATP synthesis, on the proton concentration in the intermembrane space and on oxygen consumption, giving reasons.3 marks