

MCQOPTIONS
This section includes 16 Mcqs, each offering curated multiple-choice questions to sharpen your Biochemistry knowledge and support exam preparation. Choose a topic below to get started.
1. |
FAD is reduced to FADH during |
A. | electron transport phosphorylation |
B. | lactate fermentation |
C. | Krebs cycle |
D. | glycolysis |
Answer» D. glycolysis | |
2. |
How many CO molecules are exhaled for each O molecule utilized in cellular respiration? |
A. | 1 |
B. | 3 |
C. | 6 |
D. | 12 |
Answer» B. 3 | |
3. |
In electron transport, electrons ultimately pass to |
A. | ADP |
B. | cytochrome b |
C. | oxygen |
D. | none of these |
Answer» D. none of these | |
4. |
During electron transport, protons are pumped out of the mitochondrion at each of the major sites except for |
A. | <i>complex I</i> |
B. | <i>complex II</i> |
C. | <i>complex III</i> |
D. | <i>complex IV</i> |
Answer» C. <i>complex III</i> | |
5. |
The aerobic breakdown of glucose known as respiration involves |
A. | electron transport phosphorylation |
B. | glycolysis |
C. | Krebs Cycle |
D. | all of the above |
Answer» E. | |
6. |
Which of the following is not a feature of oxidative phosphorylation? |
A. | Direct transfer of phosphate from a substrate molecule to ADP |
B. | An electrochemical gradient across the inner mitochondrial membrane |
C. | A membrane bound ATP synthase |
D. | A protonmotive force |
Answer» B. An electrochemical gradient across the inner mitochondrial membrane | |
7. |
How many CO2 molecules are exhaled for each O2 molecule utilized in cellular respiration? |
A. | 1 |
B. | 3 |
C. | 6 |
D. | 12 |
Answer» B. 3 | |
8. |
What happens after glycolysis when oxygen is available as an electron acceptor? |
A. | Pyruvate is formed |
B. | NADH is produced |
C. | Fermentation |
D. | Oxidative phosphorylation |
Answer» C. Fermentation | |
9. |
FAD is reduced to FADH2 during |
A. | electron transport phosphorylation |
B. | lactate fermentation |
C. | Krebs cycle |
D. | glycolysis |
Answer» D. glycolysis | |
10. |
During glycolysis, electrons removed from glucose are passed to |
A. | FAD |
B. | NAD |
C. | <sup>+</sup> |
D. | acetyl CoA |
E. | pyruvic acid |
Answer» C. <sup>+</sup> | |
11. |
Coenzyme Q is involved in electron transport as |
A. | directly to O |
B. | <sub>2</sub> |
C. | a water-soluble electron donor |
D. | covalently attached cytochrome cofactor |
E. | a lipid-soluble electron carrier |
Answer» E. a lipid-soluble electron carrier | |
12. |
The carbon dioxide is primary a product of |
A. | Krebs cycle |
B. | glycolysis |
C. | electron transport phosphorylation. |
D. | lactate fermentation. |
Answer» B. glycolysis | |
13. |
In aerobic respiration, the compound that enters a mitochondrion is |
A. | acetyl CoA |
B. | pyruvate |
C. | phosphoglyceraldehyde |
D. | oxaloacetate |
Answer» C. phosphoglyceraldehyde | |
14. |
A biological redox reaction always involves |
A. | an oxidizing agent |
B. | a gain of electrons |
C. | a reducing agent |
D. | all of these |
Answer» E. | |
15. |
Which of the following is correct sequence of processes in the oxidation of glucose? |
A. | Krebs cycle - glycolysis - electron transport |
B. | Glycolysis - Krebs cycle - eletron transport |
C. | Electron transport - Krebs cycle - glycolysis |
D. | Krebs cycle - electron transport - glycolysis |
Answer» C. Electron transport - Krebs cycle - glycolysis | |
16. |
The complete oxidation of glucose yields usable energy in the form of |
A. | FADH |
B. | <sub>2</sub> |
C. | coenzyme A |
D. | ATP |
E. | pyruvic acid |
Answer» D. ATP | |