Biochemistry Multiple Choice Questions on “Lipids as Signals, Cofactors, and Pigments”.
1. Phosphorylation of phosphatidylinositol yields __________
A. Phosphatidylinositol 4, 5-biphosphate
B. Phosphatidylinositol 3, 5-biphosphate
C. Phosphatidylinositol 3, 4-biphosphate
D. Phosphatidylinositol 5, 6-biphosphate
Answer: A
Clarification: Phosphorylation of phosphatidylinositol yields phosphatidylinositol 4, 5-biphosphate.
2. Which of the following vitamin is derived from cholesterol?
A. A
B. B
C. C
D. D
Answer: D
Clarification: Vitamin-D is derived from cholesterol.
3. What leads to the activation of protein kinase C?
A. Release of intracellular Ca+2 + diacylglycerol
B. Release of intracellular Mg+ + diacylglycerol
C. Release of intracellular Ca+2 + glycerol
D. Release of intracellular Ca+2 + triacylglycerol
Answer: A
Clarification: Release of intracellular Ca+2 + diacylglycerol causes activation of protein kinase C.
4. Which of the following serves as a specific binding site for the proteins involved in membrane fusion during exocytosis?
A. Phosphatidylinositol
B. Phosphatidylinositol 4, 5-biphosphate
C. Phosphatidylinositol 3, 5-biphosphate
D. Phosphatidylinositol 3, 4-biphosphate
Answer: B
Clarification: Phosphatidylinositol 4, 5-biphosphate in the cytoplasmic face of plasma membranes serves as a specific binding site for certain cytoskeletal proteins and for some soluble proteins involved in membranes fusion during exocytosis.
5. Which of the following hormone is responsible for the activation of phospholipase C?
A. Serotonin
B. Cortisol
C. Vasopressin
D. Adrenaline
Answer: C
Clarification: Vasopressin, when it binds to the plasma membrane receptors on the epithelial cells of the renal collecting duct, a specific phospholipase C is activated.
6. An example of glycerophospholipid involved in cell signaling is __________
A. Cardiolipin
B. Phosphatidic acid
C. Phosphatidylcholine
D. Phosphatidylinositol
Answer: D
Clarification: Phosphatidylinositol is involved in cell signaling.
7. Which of the following type structure contains all the three glycosphingolipids?
A. B structure
B. A structure
C. O structure
D. AB structure
Answer: C
Clarification: Type O structure has all three glycosphingolipids.
8. The lipids with potent bio activities derived from isoprenoid precursors are common in __________
A. Vitamin A, K, ubiquinone and dolichol
B. Vitamin A, D, ubiquinone and dolichol
C. Vitamin A, B, D and K
D. Vitamin A, B, K and dolichol
Answer: A
Clarification: Vitamin A, K, ubiquinone and dolichol have in common the lipids with potent bio activities derived from isoprenoid precursors.
9. Which of the following vitamin is responsible for Ca+2 and phosphate metabolism?
A. A
B. K
C. E
D. D
Answer: D
Clarification: Vitamin A –vision
Vitamin K-blood clotting
Vitamin E-prevention of oxidative damage.
10. How many products are obtained by the hydrolysis of phosphatidylinositol by phospholipase C?
A. 1
B. 2
C. 3
D. 4
Answer: B
Clarification: Inositol 1, 4, 5-triphosphate and diacylglycerol are the two products obtained by the hydrolysis of phosphatidylinositol by phospholipase C.
.