MCQOPTIONS
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MCQOPTIONS
This section includes 38 Mcqs, each offering curated multiple-choice questions to sharpen your Biochemistry knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
What do NAD, NADP, and FAD all have in common? |
| A. | They are reduced |
| B. | They have a full complement of electrons |
| C. | They are oxidized |
| D. | They are what is used during carbon fixation in photosynthesis |
| Answer» D. They are what is used during carbon fixation in photosynthesis | |
| 2. |
What do coenzyme A, CO, oxaloacetate, and FADH all have in common? |
| A. | They are all components or products of the citric acid cycle |
| B. | They are part of the dark reactions of photosynthesis |
| C. | They are part of the reactions of lactic acid fermentation |
| D. | They are all elements of oxidative phosphorylation |
| Answer» B. They are part of the dark reactions of photosynthesis | |
| 3. |
If the oxygen is labeled in CO and provide this CO to a plant, where it is expected to find this labeled oxygen after the plant had undergone photosynthesis? |
| A. | In the water used |
| B. | In the NADPH |
| C. | In the carbohydrate produced |
| D. | In the oxygen given off by the plant |
| Answer» D. In the oxygen given off by the plant | |
| 4. |
NADP is reduced to NADPH during |
| A. | light dependent reactions |
| B. | photorespiration |
| C. | calvin cylcle |
| D. | none of these |
| Answer» B. photorespiration | |
| 5. |
Where does the O come from that is essential for the proper functioning of oxidative phosphorylation? |
| A. | Fermentation |
| B. | Light reactions of photosynthesis |
| C. | Dark reactions of photosynthesis |
| D. | Carbon fixation |
| Answer» C. Dark reactions of photosynthesis | |
| 6. |
In the Calvin cycle, carbon dioxide is fixed in a reaction with the |
| A. | ribulose diphosphate |
| B. | ribulose phosphate |
| C. | ribose tri phosphate |
| D. | 3-phosphoglyceric acid |
| Answer» B. ribulose phosphate | |
| 7. |
During the light-dependent reactions of photosynthesis, which of the following does not occur? |
| A. | Splitting of water |
| B. | Carbon dioxide fixation |
| C. | Release of oxygen |
| D. | Absorption of light energy by photosystems |
| Answer» C. Release of oxygen | |
| 8. |
Oxidative phosphorylation is to respiration as __________ is to photosynthesis |
| A. | carbon fixation |
| B. | electron transport chain |
| C. | light capture by chlorophyll |
| D. | reduction of NADPH |
| Answer» C. light capture by chlorophyll | |
| 9. |
In cells having organelles, the steps of the Krebs cycle and the electron transport system occur in the |
| A. | cell membrane |
| B. | mitochondria |
| C. | endoplasmic reticulum |
| D. | none of these |
| Answer» C. endoplasmic reticulum | |
| 10. |
Which of the following structures or processes are logically associated with chloroplasts? |
| A. | Plant cells |
| B. | Chlorophyll |
| C. | Thylakoid membranes |
| D. | All of these |
| Answer» E. | |
| 11. |
What do NAD+, NADP+, and FAD+ all have in common? |
| A. | They are reduced |
| B. | They have a full complement of electrons |
| C. | They are oxidized |
| D. | They are what is used during carbon fixation in photosynthesis |
| Answer» D. They are what is used during carbon fixation in photosynthesis | |
| 12. |
Which enzyme is involved in carbon-fixation reaction? |
| A. | NADP reductase |
| B. | Cytochrome reductase |
| C. | Ribulose bisphosphate carboxylase |
| D. | Glycerol kinase |
| Answer» D. Glycerol kinase | |
| 13. |
In the initial step of photosynthesis, sunlight energizes the electron pair of |
| A. | adenosine triphosphate (ATP) |
| B. | chlorophyll pigments |
| C. | water |
| D. | carbon dioxide |
| Answer» C. water | |
| 14. |
A cyclic electron transport process is the characteristic of |
| A. | photosynthesis |
| B. | methane oxidation |
| C. | sulfide oxidation |
| D. | methane production |
| Answer» B. methane oxidation | |
| 15. |
Antenna complexes, electron transport chains, and carbon fixation are all found in |
| A. | animal cells |
| B. | bacterial cells |
| C. | plant cells |
| D. | association with the reactions of the citric acid cycle |
| Answer» D. association with the reactions of the citric acid cycle | |
| 16. |
Where does the O2 come from that is essential for the proper functioning of oxidative phosphorylation? |
| A. | Fermentation |
| B. | Light reactions of photosynthesis |
| C. | Dark reactions of photosynthesis |
| D. | Carbon fixation |
| Answer» C. Dark reactions of photosynthesis | |
| 17. |
In oxygenic photosynthesis, the electron donor is |
| A. | water |
| B. | oxygen |
| C. | NADH |
| D. | NADPH |
| Answer» B. oxygen | |
| 18. |
The vast majority of the molecules that act as energy carriers to power cellular activities are made in |
| A. | the nucleus |
| B. | the Golgi apparatus |
| C. | the cytosol |
| D. | the mitochondria and chloroplasts |
| Answer» E. | |
| 19. |
More ATP is manufactured during __________ than at any other time in all of cellular metabolism. |
| A. | fermentation |
| B. | glycolysis |
| C. | the light reactions of photosynthesis |
| D. | oxidative phosphorylation |
| Answer» E. | |
| 20. |
Electron transport systems play a vital role in |
| A. | Calvin cycle |
| B. | photorespiration |
| C. | light-dependent reactions |
| D. | all of these |
| Answer» D. all of these | |
| 21. |
The electrons that are released by the splitting of water during photosynthesis ultimately end up in |
| A. | ATP |
| B. | O |
| C. | <sub>2</sub> |
| D. | NADPH |
| E. | rubisco |
| Answer» D. NADPH | |
| 22. |
Carbon dioxide is reduced in |
| A. | noncyclic photophosphorylation |
| B. | the Calvin cycle |
| C. | the light reactions |
| D. | both light and dark reactions |
| Answer» C. the light reactions | |
| 23. |
In noncyclic photophosphorylation, the ultimate acceptor of electrons that have been produced from the splitting of water is |
| A. | NADP |
| B. | <sup>+</sup> |
| C. | chlorophyll a |
| D. | carbon dioxide |
| E. | chlorophyll b |
| Answer» D. carbon dioxide | |
| 24. |
The breakdown of glucose occurs by the process known as |
| A. | glycolysis |
| B. | fermentation |
| C. | anaerobic respiration |
| D. | Krebs cycle |
| Answer» B. fermentation | |
| 25. |
The manufacture of ATP in both photosynthesis and respiration is made possible by |
| A. | the existence of a proton gradient across specific membranes |
| B. | the action of ATP synthase |
| C. | energy from the movement of electrons |
| D. | All of the above |
| Answer» E. | |
| 26. |
In algae, photosynthesis takes place in |
| A. | choloroplasts |
| B. | cell membrane |
| C. | mitochondria |
| D. | none of the above |
| Answer» B. cell membrane | |
| 27. |
What is the maximum absorption wavelength for photosystem I in green plants? |
| A. | 550 nm |
| B. | 600 nm |
| C. | 700 nm |
| D. | 750 nm |
| Answer» D. 750 nm | |
| 28. |
Which one of the following is a product of both cyclic and noncyclic photophosphorylation? |
| A. | NADPH |
| B. | O |
| C. | <sub>2</sub> |
| D. | ATP |
| E. | Carbohydrate |
| Answer» D. ATP | |
| 29. |
Which of the following represents a correct ordering of the events that occur during the respiration of glucose in the absence of O2? |
| A. | Glycolysis; citric acid cycle; oxidative phosphorylation |
| B. | Glycolysis; oxidative phosphorylation; citric acid cycle |
| C. | Oxidative phosphorylation; citric acid cycle; glycolysis |
| D. | Glycolysis; fermentation |
| Answer» E. | |
| 30. |
Glycolysis takes places in the __________ and produces __________ , which in the presence of oxygen then enters the __________ . |
| A. | cytosol; glucose; mitochondrion to complete fermentation |
| B. | cytosol; pyruvate; mitochondrion to complete fermentation |
| C. | cytosol; pyruvate; mitochondrion to complete cellular respiration |
| D. | mitochondrion; pyruvate; chloroplast to complete photosynthesis |
| Answer» D. mitochondrion; pyruvate; chloroplast to complete photosynthesis | |
| 31. |
What process in cellular respiration is essentially the reverse of carbon fixation in photosynthesis? |
| A. | Glycolysis |
| B. | Citric acid cycle |
| C. | Oxidative phosphorylation |
| D. | Alcohol fermentation |
| Answer» C. Oxidative phosphorylation | |
| 32. |
What do coenzyme A, CO2, oxaloacetate, and FADH2 all have in common? |
| A. | They are all components or products of the citric acid cycle |
| B. | They are part of the dark reactions of photosynthesis |
| C. | They are part of the reactions of lactic acid fermentation |
| D. | They are all elements of oxidative phosphorylation |
| Answer» B. They are part of the dark reactions of photosynthesis | |
| 33. |
The followings are the products of the light reactions of photosynthesis except |
| A. | ATP |
| B. | oxygen |
| C. | NADPH |
| D. | glucose |
| Answer» E. | |
| 34. |
Carbon fixation requires the expenditure of ATP molecules which is generated by |
| A. | formation of glucose during the Calvin cycle |
| B. | replenishment of chlorophyll |
| C. | ETS (electron transfer system) during the light reactions |
| D. | none of the above |
| Answer» D. none of the above | |
| 35. |
The cytochrome c oxidase complex |
| A. | accepts electrons from cyt c |
| B. | donates four electrons to O |
| C. | <sub>2</sub> |
| D. | pumps protons out of the matrix space |
| E. | all of these |
| Answer» E. all of these | |
| 36. |
NADP+ is reduced to NADPH during |
| A. | light dependent reactions |
| B. | photorespiration |
| C. | calvin cylcle |
| D. | none of these |
| Answer» B. photorespiration | |
| 37. |
If the oxygen is labeled in CO2 and provide this CO2 to a plant, where it is expected to find this labeled oxygen after the plant had undergone photosynthesis? |
| A. | In the water used |
| B. | In the NADPH |
| C. | In the carbohydrate produced |
| D. | In the oxygen given off by the plant |
| Answer» D. In the oxygen given off by the plant | |
| 38. |
As a result of the photosynthetic process, which product is formed? |
| A. | Oxygen |
| B. | Water |
| C. | Carbon dioxide |
| D. | Both (a) and (b) |
| Answer» B. Water | |