Question

7. What would happen to the ATP yield of cellular respiration if

(a) the transporter that imports pyruvate into the mitochondria stopped working? Explain.

(b) the transporter that imports pyruvate into the mitochondria worked only at 10% of its normal capacity? Explain.

(c) The inner membrane of the mitochondria became affected by an antibiotic that prevented the buildup of a proton gradient. Explain.

(d) ATP synthase started to make one ATP per proton. Explain.

Answer 1

7.

A)If transporter that imports pyruvate in mitochondria stops working then the net yield of ATP will just be 2 ATP.

B) If transporter that transports Pyruvate into mitochondria works at 10% efficiency then only 10 in 100 pyruvate molecules will be transported which means that the net ATP yield after the glycolysis step reduces to 10%.

C) If the mitochondrial membrane that builds up proton gradient is affected by antibiotic then only that ATP which is directly formed will be present.There will be no formation of ATP through FADH2,NADH2.

So ATP will be produced only by substrate level phosphorylation.Therefore only 2 ATP are produced.

D)If ATP synthase starts making one ATP per proton then number of ATP produced by NADH is equal to number of ATP produced by FADH2.So in aerobic respiration 3 NADH and 1 FADH2 are produced so in total 5 ATP will now be produced.Therfore the total yield of ATP will be 7ATP in one cycle.