Bioenergetics mcqs || MDCAT test preparation

Cellular Respiration of Proteins and Fats – MDCAT MCQs

1. Which molecule is produced after the hydrolysis of fats?
A. Glucose
B. Pyruvate
C. Glycerol and fatty acids
D. Acetyl-CoA

2. Glycerol is converted into which intermediate of glycolysis?
A. Pyruvate
B. Acetyl-CoA
C. Fructose-1,6-bisphosphate
D. Glyceraldehyde-3-phosphate

3. Fatty acids are directly converted into:
A. Glucose
B. Glycerol
C. Acetyl-CoA
D. Pyruvate

4. Which process do fatty acids enter after being converted to Acetyl-CoA?
A. Glycolysis
B. Electron transport chain
C. Fermentation
D. Krebs cycle

5. In the absence of carbohydrates, the body primarily uses:
A. Oxygen
B. Nucleic acids
C. Fats
D. Water

6. During illness, the body begins to utilize:
A. Carbohydrates
B. Minerals
C. Proteins
D. Vitamins

7. Deamination of amino acids leads to the production of:
A. Acetyl-CoA
B. NH₃ (ammonia)
C. Glycerol
D. Pyruvate

8. Ammonia produced from deamination enters which cycle?
A. Krebs cycle
B. Glycolysis
C. Calvin cycle
D. Urea cycle

9. Which of the following is not a product of fat hydrolysis?
A. Glycerol
B. Glucose
C. Fatty acids
D. None of these

10. A molecule's R-group determines if an amino acid is oxidized in:
A. Only in glycolysis
B. Only in the Krebs cycle
C. Either in glycolysis or Krebs cycle
D. None of the above

11. What is the first step in the utilization of protein for energy?
A. Deamination
B. Glycolysis
C. Beta oxidation
D. Transamination

12. Which process breaks down fatty acids into Acetyl-CoA?
A. Beta-oxidation
B. Glycolysis
C. Krebs cycle
D. Urea cycle

13. Glycerol enters the respiration pathway at the level of:
A. G3P (Glyceraldehyde-3-Phosphate)
B. Pyruvate
C. Acetyl-CoA
D. Oxaloacetate

14. The final common pathway for all macronutrient metabolism is:
A. Glycolysis
B. Krebs cycle
C. Urea cycle
D. Calvin cycle

15. Which macronutrient is primarily used in normal conditions for energy?
A. Carbohydrates
B. Proteins
C. Fats
D. Nucleic acids

16. During prolonged starvation, the body shifts to using:
A. Glycogen
B. Glucose
C. Fat reserves
D. Water

17. Amino acids are used for energy when:
A. The body is under stress or illness
B. After a meal
C. During exercise only
D. Never

18. Which step comes first in aerobic respiration of glucose?
A. Glycolysis
B. Krebs cycle
C. Oxidative phosphorylation
D. Beta oxidation

19. What happens to NH₃ (ammonia) formed from amino acid breakdown?
A. Used for ATP production
B. Enters the urea cycle
C. Exhaled as gas
D. Converted to glucose

20. Which of the following is NOT directly involved in energy production?
A. Urea cycle
B. Krebs cycle
C. Glycolysis
D. Oxidative phosphorylation