citric acid cycle
All of the following vitamins are required in citric acid cycle, EXCEPT:
| A |
Riboflavin |
|
| B |
Niacin |
|
| C |
Thiamin |
|
| D |
Ascorbic acid |
All of the following vitamins are required in citric acid cycle, EXCEPT:
| A |
Riboflavin |
|
| B |
Niacin |
|
| C |
Thiamin |
|
| D |
Ascorbic acid |
The citric acid cycle is inhibited by which of the following?
| A |
Fluoroacetate |
|
| B |
Fluorouracil |
|
| C |
Arsenic |
|
| D |
Aerobic conditions |
The citric acid cycle is inhibited by which of the following?
| A |
Fluoroacetate |
|
| B |
Fluorouracil |
|
| C |
Arsenic |
|
| D |
Aerobic conditions |
Fluoroacetate can be converted to fluorocitrate, which is an inhibitor of aconitase. Arsenic is not a direct inhibitor, but arsenite is an inhibitor of lipoic acid–containing enzymes such as α-ketoglutarate dehydrogenase. Malonate, not malic acid, is an inhibitor of succinate dehydrogenase. The citric acid cycle requires oxygen and would be inhibited by anaerobic, not aerobic, conditions. Fluorouracil is a suicide inhibitor of thymidylate synthase and blocks deoxythymidylate synthesis.
In vivo control of citric acid cycle is effected by:
| A |
Acetyl CoA |
|
| B |
Coenzyme A |
|
| C |
ATP |
|
| D |
Citrate |
In vivo control of citric acid cycle is effected by:
| A |
Acetyl CoA |
|
| B |
Coenzyme A |
|
| C |
ATP |
|
| D |
Citrate |
C i.e. ATP, E i.e. NADH
Which end product of citric acid cycle is used in detoxification of ammonia in brain?
| A |
Oxaloacetate |
|
| B |
Alphaketoglutarate |
|
| C |
Succinate |
|
| D |
Citrate |
Which end product of citric acid cycle is used in detoxification of ammonia in brain?
| A |
Oxaloacetate |
|
| B |
Alphaketoglutarate |
|
| C |
Succinate |
|
| D |
Citrate |
All are components of Citric acid cycle EXCEPT:
| A |
Fumarase |
|
| B |
Malonate |
|
| C |
Succinate dehydrogenase |
|
| D |
Alpha-ketoglutarate dehydrogenase |
All are components of Citric acid cycle EXCEPT:
| A |
Fumarase |
|
| B |
Malonate |
|
| C |
Succinate dehydrogenase |
|
| D |
Alpha-ketoglutarate dehydrogenase |
Malonate competitively inhibits succinate dehydrogenase, which converts succinate to fumarate
Which of the following glucogenic amino acid enters the citric acid cycle at succinyl CoA
| A |
Phenylalanine |
|
| B |
Tyrosine |
|
| C |
Isoleucine |
|
| D |
Tryptophan |
Which of the following glucogenic amino acid enters the citric acid cycle at succinyl CoA
| A |
Phenylalanine |
|
| B |
Tyrosine |
|
| C |
Isoleucine |
|
| D |
Tryptophan |
Ans. is ‘c’ i.e., isoleucine
Not an intermediate product of citric acid cycle is:
| A |
Acyl Co-A |
|
| B |
Succinyl Co-A |
|
| C |
Citrate |
|
| D |
a-ketoglutarate |
Not an intermediate product of citric acid cycle is:
| A |
Acyl Co-A |
|
| B |
Succinyl Co-A |
|
| C |
Citrate |
|
| D |
a-ketoglutarate |
Ans. a. Acetyl Co-A
Substrate level phosphorylation is seen in reaction catalyzed by which enzyme of citric acid cycle‑
| A |
Pyruvate kinase |
|
| B |
Succinate thiokinase |
|
| C |
Phosphoglycerate kinase |
|
| D |
All of the above |
Substrate level phosphorylation is seen in reaction catalyzed by which enzyme of citric acid cycle‑
| A |
Pyruvate kinase |
|
| B |
Succinate thiokinase |
|
| C |
Phosphoglycerate kinase |
|
| D |
All of the above |
Ans. is ‘b’ i.e., Succinate thiokinase
