

MCQOPTIONS
This section includes 51 Mcqs, each offering curated multiple-choice questions to sharpen your VITEEE knowledge and support exam preparation. Choose a topic below to get started.
1. |
The mechanism of action of cyanide, a mitochondrial toxin, is by inhibiting |
A. | ATP synthase |
B. | Succinate dehydrogenase |
C. | Cytochrome c oxidase |
D. | NADH dehydrogenase |
Answer» D. NADH dehydrogenase | |
2. |
Mitochondrial DNA is one of the best marker tools for population biologists and evolutionary biologists because |
A. | Absence of genetic recombination in mt-DNA |
B. | Mitochondrial genes are specific to mt-DNA |
C. | It can be easily isolated |
D. | It undergoes spontaneous mutation |
Answer» B. Mitochondrial genes are specific to mt-DNA | |
3. |
Typically how many copies of DNA is/are there in each mitochondrion? |
A. | 1 |
B. | 11 |
C. | 10 |
D. | 12 |
Answer» D. 12 | |
4. |
The size of plant mitochondrial DNA is |
A. | 16kb |
B. | 200-2500kb |
C. | 100- 2550kb |
D. | 100-2500kb |
Answer» C. 100- 2550kb | |
5. |
The size of human mitochondrial DNA is |
A. | 16kb |
B. | 200kb |
C. | 2500kb |
D. | 100kb |
Answer» B. 200kb | |
6. |
More than what proportion of mitochondrial proteins are coded by nuclear DNA? |
A. | 95% |
B. | 50% |
C. | 10% |
D. | 40% |
Answer» B. 50% | |
7. |
Oxysomes or F0 – F1 particles occur on |
A. | Inner mitochondrial membrane |
B. | Chloroplast surface |
C. | Mitochondrial surface |
D. | Thylakoids |
Answer» B. Chloroplast surface | |
8. |
Mitochondrial DNA is a |
A. | Simple, single stranded linear DNA molecule |
B. | Simple, single stranded circular DNA molecule |
C. | Simple, double stranded linear DNA molecule |
D. | Simple, double stranded circular DNA molecule |
Answer» E. | |
9. |
How many mitochondrial proteins are encoded in nuclear genes and imported into mitochondria after their synthesis? |
A. | 600 |
B. | 700 |
C. | 800 |
D. | 900 |
Answer» E. | |
10. |
How many human mitochondrial proteins are encoded in the mitochondrial genome and synthesized within mitochondria? |
A. | 11 |
B. | 12 |
C. | 13 |
D. | 1`4 |
Answer» D. 1`4 | |
11. |
The effect of increased levels of hydrogen ions in the inter-membrane space of the mitochondria is |
A. | Increase ATP production |
B. | Decreased levels of oxidative phosphorylation |
C. | Increased levels of water in inter-membrane space |
D. | Decreased levels of chemiosmosis |
Answer» B. Decreased levels of oxidative phosphorylation | |
12. |
Products of glucose oxidation essential for oxidative phosphorylation are |
A. | Pyruvate |
B. | Acetyl co-A |
C. | NADPH and ATP |
D. | NADH and FADH2 |
Answer» E. | |
13. |
NADP+ in its reduced form is |
A. | NAD |
B. | NADH |
C. | NADPH |
D. | None |
Answer» D. None | |
14. |
What is the proportion of ATP produced by oxidative phosphorylation? |
A. | 60% |
B. | 70% |
C. | 80% |
D. | 90% |
Answer» B. 70% | |
15. |
NADP is a cofactor used in |
A. | Catabolic reactions |
B. | Anabolic reactions |
C. | Elimination reaction |
D. | Redox reactions |
Answer» C. Elimination reaction | |
16. |
In metabolism, NAD is involved in |
A. | Spontaneous reaction |
B. | Elimination reaction |
C. | Redox reactions |
D. | None |
Answer» D. None | |
17. |
Where does oxidative phosphorylation take place? |
A. | Ribosomes |
B. | Nucleus |
C. | Mitochondria |
D. | Cell membrane |
Answer» D. Cell membrane | |
18. |
The magnitude of proton motive force depends on |
A. | Energy charge of cell |
B. | Permeability of membrane |
C. | Number of ribosomes in cell |
D. | None |
Answer» B. Permeability of membrane | |
19. |
The rate of electron transfer when proton motive force is high is |
A. | Faster |
B. | Slower |
C. | Moderate |
D. | None |
Answer» C. Moderate | |
20. |
The regulation of oxidative phosphorylation depends on |
A. | Magnitude of ion motive force |
B. | Magnitude of electron motive force |
C. | Magnitude of proton motive force |
D. | None |
Answer» D. None | |
21. |
Maximum energy per gram on oxidation is yielded from |
A. | Starch |
B. | Fat |
C. | Glycogen |
D. | Protein |
Answer» C. Glycogen | |
22. |
Long-chain fatty acids are oxidized step-wise in one carbon units starting from |
A. | Carboxyl end |
B. | Aliphatic end |
C. | a and b |
D. | None |
Answer» B. Aliphatic end | |
23. |
Membrane potential and proton gradient |
A. | Cancel one another when uncouplers are present |
B. | Reinforce one another when respiratory inhibitors are present |
C. | Are sufficient, separately to make ATP from ADP + Pi |
D. | Are required to make ATP |
Answer» E. | |
24. |
Every cycle of β-oxidation produces |
A. | 1 FAD, 1 NAD+ and 2 CO2 molecules |
B. | 1 FADH2, 1 NADH and 1 acetyl co-A |
C. | 1 FADH2, 1 NAD+ and 1 acetyl co-A |
D. | 1 FAD, 1 NADH and 2 CO2 molecules |
Answer» C. 1 FADH2, 1 NAD+ and 1 acetyl co-A | |
25. |
The acyl co-A formed in the cytosol is transported to |
A. | Mitochondrial matrix |
B. | Microsomes |
C. | ER |
D. | Remains in cytosol |
Answer» B. Microsomes | |
26. |
Three identical β subunits of the F1 complex during ATP synthesis have |
A. | Different affinities for ATP and ADP |
B. | Similar affinities for ADP and ATP |
C. | Different affinities for ADP but not ATP |
D. | Different affinities for ATP but not ADP |
Answer» B. Similar affinities for ADP and ATP | |
27. |
The transport of acyl co-A for oxidation using a shuttle involves formation of the intermediate |
A. | Acyl coenzyme A |
B. | 3 acetyl co-A |
C. | Acyl cartinine |
D. | None |
Answer» D. None | |
28. |
The measure of potential energy stored as combination of proton and voltage gradients across membrane is termed as |
A. | Proton motive force |
B. | Electron motive force |
C. | Molecule motive force |
D. | Ion motive force |
Answer» B. Electron motive force | |
29. |
ATP synthesis by chemiosmosis is by |
A. | ATP dehydrogenase |
B. | Gyrase |
C. | ATP synthase |
D. | Dehydrogenase |
Answer» D. Dehydrogenase | |
30. |
The proposal of chemiosmotic hypothesis was by |
A. | Peter D. Mitchell |
B. | Charles Darwin |
C. | Mendele |
D. | Alfred Russell |
Answer» B. Charles Darwin | |
31. |
Which of the following accepts only one electron? |
A. | Cytochrome b |
B. | Coenzyme Q |
C. | FMN |
D. | FAD |
Answer» B. Coenzyme Q | |
32. |
Out of the following the one having highest redox potential is |
A. | Ubiquinone |
B. | O2 |
C. | FMN |
D. | NAD |
Answer» C. FMN | |
33. |
Chemiosmotic hypothesis does not involve |
A. | Only proton transport is strictly regulated, other positively charged ions can diffuse freely across the mitochondrial membrane |
B. | ATPase activity is reversible |
C. | Proton flow in to the mitochondria depends on the presence of ADP and Pi |
D. | Electron transport by the respiratory chain pumps protons out of the mitochondria |
Answer» B. ATPase activity is reversible | |
34. |
Which of the following takes place in substrate level phosphorylation? |
A. | Oxidation of one molecule of substrate is linked to synthesis of more than one ATP molecule |
B. | High energy intermediate compounds cannot be isolated |
C. | Only mitochondrial reactions participate in ATP formation |
D. | Substrate reacts to form a product containing a high energy bond |
Answer» E. | |
35. |
If rotenone is added to the mitochondrial electron transport chain |
A. | Succinate oxidation remains normal |
B. | P: O ratio of NADH is reduced from 3:1 to 2:1 |
C. | Oxidative phosphorylation is uncoupled at site I |
D. | Rate of NADH oxidation is diminished to two-thirds of its initial value |
Answer» B. P: O ratio of NADH is reduced from 3:1 to 2:1 | |
36. |
If the oxidative phosphorylation was uncoupled in the mitochondria then there is a/an |
A. | Decreased concentration of ADP in the mitochondria |
B. | Decreased oxidative rate |
C. | Increased inorganic phosphate in the mitochondria |
D. | Decreased production of heat |
Answer» D. Decreased production of heat | |
37. |
If the oxidative phosphorylation was uncoupled in the mitochondria then there is a/an |
A. | Decreased concentration of ADP in the mitochondria |
B. | Decreased oxidative rate |
C. | Increased inorganic phosphate in the mitochondria |
D. | Decreased production of heat |
Answer» D. Decreased production of heat | |
38. |
If 2, 4-dinitrophenol is added to tightly coupled mitochondria that are actively oxidizing succinate |
A. | Electron flow will continue but ATP synthesis will not occur |
B. | Electron flow will continue but ATP synthesis will be increased |
C. | Electron flow will cease but ATP synthesis will continue |
D. | Both electron flow and ATP synthesis will be ceased |
Answer» B. Electron flow will continue but ATP synthesis will be increased | |
39. |
If mitochondria were blocked at the site of NADH oxidation and were treated with succinate as substrate, what would the P : O ratio is? |
A. | Same as that normally produced by succinate |
B. | One more than normally produced by succinate |
C. | One less than normally produced by succinate |
D. | Zero |
Answer» B. One more than normally produced by succinate | |
40. |
Effect of valinomycin on oxidative phosphorylation does not involve |
A. | pH gradient across the inner mitochondrial membrane decreases |
B. | Rate of flow of electrons increases |
C. | Rate of oxygen consumption increases |
D. | Net yield of ATP decreases |
Answer» B. Rate of flow of electrons increases | |
41. |
Which of the following is the prosthetic group of NADH dehydrogenase? |
A. | NADH |
B. | FAD |
C. | NADPH |
D. | FMN |
Answer» E. | |
42. |
In mitochondria, hydride ions are removed from substrates by |
A. | NAD-linked dehydrogenases |
B. | NADP-linked dehydrogenases |
C. | ATP synthase |
D. | Succinate dehydrogenases |
Answer» B. NADP-linked dehydrogenases | |
43. |
Complex 4 is also called |
A. | NADH dehydrogenase |
B. | Succinate dehydrogenase |
C. | Cytochrome bc1 complex |
D. | Cytochrome oxidase |
Answer» E. | |
44. |
Complex 3 is also called |
A. | NADH dehydrogenase |
B. | Succinate dehydrogenase |
C. | Cytochrome bc1 complex |
D. | Cytochrome oxidase |
Answer» D. Cytochrome oxidase | |
45. |
Complex 2 is also called |
A. | NADH dehydrogenase |
B. | Succinate dehydrogenase |
C. | Cytochrome bc1 complex |
D. | Cytochrome oxidase |
Answer» C. Cytochrome bc1 complex | |
46. |
Complex 1 is also called |
A. | NADH dehydrogenase |
B. | Succinate dehydrogenase |
C. | Cytochrome bc1 complex |
D. | Cytochrome oxidase |
Answer» B. Succinate dehydrogenase | |
47. |
The first step in the β oxidation of fatty acyl co-A is catalyzed by |
A. | Succinate dehydrogenase |
B. | NADH dehydrogenase |
C. | ATP synthase |
D. | Acyl co-A dehydrogenase |
Answer» E. | |
48. |
The only membrane bound enzyme in the citric acid cycle is |
A. | Succinate dehydrogenase |
B. | NADH dehydrogenase |
C. | ATP synthase |
D. | Acyl co-A dehydrogenase |
Answer» B. NADH dehydrogenase | |
49. |
A lipid-soluble benzoquinone with a long isoprenoid side chain |
A. | Ubiquinone |
B. | Cytochrome b |
C. | Cytochrome c |
D. | Cytochrome a |
Answer» B. Cytochrome b | |
50. |
NADP-linked dehydrogenase catalyzes |
A. | Glucose 6-phosphate+NADP+ ↔ 6-phosphogluconate + NADPH + H+ |
B. | Lactate + NAD+ ↔ pyruvate + NADH + H+ |
C. | Pyruvate + CoA + NAD+ ↔ acetyl-CoA + CO2 + NADH + H+ |
D. | L-Malate + NAD+ ↔ oxaloacetate + NADH + H+ |
Answer» B. Lactate + NAD+ ↔ pyruvate + NADH + H+ | |