Biochemistry Multiple Choice Questions on “Biosynthesis of Triacylglycerols”.
1. Which of the following is not true regarding the synthesis of triacylglycerol in adipose tissue?
A. Phosphatidate is hydrolyzed
B. Glycerol 3-phosphate dehydrogenase plays an important role
C. Glycerol kinase plays an important role
D. It is synthesized from dihydroxyacetone phosphate
Answer: C
Clarification: The enzyme glycerol kinase has no role to play in the synthesis of triacylglycerol.
2. Hydrolysis of phosphatidic acid by phosphatidic acid phosphatase yields ___________
A. 1, 2-diacylglycerol
B. 1, 3-diacylglycerol
C. 1, 4-diacylglycerol
D. 1, 5-diacylglycerol
Answer: A
Clarification: In the pathway to triacylglycerols, phosphatidic acid is hydrolyzed by phosphatidic acid phosphatase to form a 1, 2-diacylglycerol.
3. In animal tissues, triacylglycerols and glycerophospholipids share two precursors ___________
A. Fatty acyl co-A and L-glycerol 3-phosphate
B. L-glycerol 3-phosphate and L-glycerol 2-phosphate
C. Diacylglycerol 3-phosphate and L-glycerol 3-phosphate
D. L-glycerol 3-phosphate and diacylglycerol 2-phosphate
Answer: A
Clarification: In animal tissues, triacylglycerols and glycerophospholipids share two precursors fatty acyl co-A and L-glycerol 3-phosphate.
4. Which of the following is more commonly called phosphatidic acid?
A. Diacylglycerol 3-phosphate
B. Fatty acyl co-A
C. L-glycerol 3-phosphate
D. L-glycerol 2-phosphate
Answer: A
Clarification: Diacylglycerol 3-phosphate is more commonly called phosphatidic acid or phosphatidate.
5. Where does the triacylglycerol form?
A. Liver
B. Kidneys
C. Adipose tissue
D. Heart
Answer: A
Clarification: Triacylglycerol formed in the liver is transported in the blood back to adipose tissue.
6. In adipose tissue, glyceroneogenesis couples with ___________
A. Reesterification
B. Esterification
C. Glycolysis
D. Phosphorylation
Answer: A
Clarification: In adipose tissue, glyceroneogenesis coupled with reesterification of free fatty acids controls the rate of fatty acid release to the blood.
7. Which of the following class of drugs reduce the levels of fatty acids circulating in the blood?
A. Thiazolidinediones
B. Amphetamines
C. Cathinones
D. Synthetic cannabinoids
Answer: A
Clarification: Thiazolidinediones reduce the levels of fatty acids circulating in the blood and increase sensitivity to insulin.
8. The higher activity of which of the following enzymes leads to increased synthesis of the precursors of glyceroneogenesis?
A. PEP carboxykinase
B. Acyl transferase
C. Acyl co-A synthase
D. Phosphatidic acid phosphatase
Answer: A
Clarification: The higher activity of PEP carboxykinase leads to increased synthesis of the precursors of glyceroneogenesis.
9. Dihydroxyacetone phosphate precursor of glycerol 3-phosphate is derived from ___________
A. Glycerol
B. Triacylglycerol
C. Glycerol 3-phosphate
D. Pyruvate
Answer: D
Clarification: Dihydroxyacetone phosphate precursor of glycerol 3-phosphate is derived from pyruvate via glyceroneogenesis.
10. Biological steroid derived from cholesterol is ___________
A. Clenbuterol
B. Cortisol
C. Winstrol
D. Dianabol
Answer: B
Clarification: Biological steroid derived from cholesterol is cortisol.
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