In aerobic respiration, the Krebs cycle is regarded as a series of small steps. One of these steps is the conversion of succinate to fumarate by an enzyme, succinate dehydrogenase.

a. State the role played by dehydrogenase enzymes in the Krebs cycle and explain briefly the importance of this role in the production of ATP.

b. An investigation was carried out into the effect of different concentrations of aluminium ions on the activity of succinate dehydrogenase. The enzyme concentration and all other conditions were kept constant. The graph below shows the results of this investigation.

With reference to the graph:

i. Describe the effect of the concentration of aluminium ions on the rate of production of fumarate

ii. Suggest an explanation for this effect.

Transcribed Image Text:

65 60 55 50 - 45 40 35 20 40 60 80 100 120 Concentration of aluminium ions/umol Rate of fumarate production/mmol min