MCQs on Electron Transport System
Q. Cytochromes are present in
(a) lysosomes
(b) mitochondrial matrix
(c) cristae of mitochondria
(d) outer membrane of mitochondria
Answer: : (c)
Q. ATP synthesis by ATP synthase is driven by the movement of
(a) protons
(b) NADH
(c) electrons
(d) All of the above
Answer: : (a)
Q. Oxidative phosphorylation results in the formation of
(a) Oxygen
(b) ADP
(c) ATP + H2O
(d) NADH
Answer: : (c)
Q. Which of the following complexes of ETS does not account for the pumping out of protons from the mitochondrial matrix?
(a) Complex I
(b) Complex III
(c) Complex II
(d) Complex IV
Answer: : (c)
Q. Which of the following is the Complex IV of ETS?
(a) NADH dehydrogenase
(b) Cytochrome c oxidase
(c) Cytochrome bc1
(d) Succinate dehydrogenase
Answer: : (b)
Q. Which of the following is the Complex II of ETS?
(a) NADH dehydrogenase
(b) Succinate dehydrogenase
(c) Cytochrome bc1
(d) ATP synthase
Answer: : (b)
Q. Which of the following products of glucose oxidation are necessary for oxidative phosphorylation?
(a) Pyruvate
(b) NADH and FADH2
(c) Acetyl CoA
(d) NADPH and ATP
Answer: : (b)
Q. Which of the following is true for cytochrome c oxidase complex?
(a) It donates electrons to O2
(b) It accepts electrons from Cyt c
(c) It pumps two protons out of the mitochondrial matrix
(d) All of the above
Answer: : (d)
Q. Which of the following is the correct sequence of electron acceptors in ETS for production of ATP?
(a) Cyt b, c, a, a3
(b) Cyt a, a, b, c
(c) Cyt c, b, a, a3
(d) Cyt b, c, a3, a
Answer: : (a)
Q. Which of the following terminal cytochromes is responsible for donating electrons to oxygen?
(a) Cyt a3
(b) Cyt b
(c) Cyt c
(d) Cyt a1
Answer: : (a)
Q. Electron transport system (ETS) is present in which of the following parts of mitochondria?
(a) Inner membrane
(b) Outer membrane
(c) Matrix
(d) Stroma
Answer: : (a)
Q. Which of the following is the first complex (Complex I) of ETS?
(a) NADH dehydrogenase
(b) Cytochrome aa3
(c) Cytochrome bc1
(d) ATP synthase
Answer: : (a)
Q. Which of the following is the Complex III of ETS?
(a) NADH dehydrogenase
(b) Cytochrome aa3
(c) Cytochrome bc1
(d) ATP synthase
Answer: : (c)
Q. Ubiquinone transfers its electrons to
(a) Complex I
(b) Complex II
(c) matrix
(d) Cyt c
Answer: : (d)
Q. In which part of the cell, oxidative phosphorylation takes place?
(a) Inner mitochondrial membrane
(b) Outer mitochondrial membrane
(c) Grana of chloroplast
(d) Stroma of chloroplast
Answer: : (a)
