Exam 3 (Inhibitors)

Question 1

antimycin A

Answer 1

• inhibits complex III at the Q cycle
• NADH, Q, cyt b are reduced
• cyt c1, cyt c, cyt a, and cyt a3 are oxidized

Question 2

rotenone

Answer 2

• inhibits transfer of electros from complex I to Q
• NADH is reduced
• Q, cyt b, cyt c1, cyt c, cyt a, and cyt a3 are oxidized

Question 3

cyanide or CO

Answer 3

• prevents electron transfer to O2
• everything is reduced
• O2 is oxidized

Question 4

oligomycin

Answer 4

• binds to c ring and prevents protons from flowing back to the matrix by binding to critical glutamate residue
• H+ builds up in intermembrane space

Question 5

DNP

Answer 5

• allows protons to flow back into matrix without going through ATP synthase
• ETC is happening, but no ATP is being made
• briefly used as a weight loss drug