1. Which of the following is NOT a class of lipids discussed in this module?
A) Fatty acids
B) Triacylglycerol
C) Phospholipids
D) Cholesterol
E) All of the above are discussed in this module
Answer: A) Fatty acids. Explanation: The previous module focused on the synthesis of fatty acids, while
this module focuses on the synthesis of three classes of lipids: triacylglycerol, phospholipids, and
cholesterol.
2. What is the precursor of both storage lipids and many membrane lipids?
A) Cholesterol
B) Triacylglycerol
C) Phosphatidate
D) AcetylCoA
E) None of the above
Answer: C) Phosphatidate. Explanation: Phosphatidate is a precursor of both storage lipids and many
membrane lipids.
3. How is cholesterol synthesized from acetylCoA?
A) Through a series of reactions involving enzymes and intermediates
B) Through a single-step reaction
C) Through a process of diffusion
D) Through a process of osmosis
E) None of the above
Answer: A) Through a series of reactions involving enzymes and intermediates. Explanation:
Cholesterol is synthesized from acetylCoA through a series of reactions involving enzymes and
intermediates.
4. How is cholesterol synthesis regulated?
A) By the availability of acetylCoA
B) By the activity of the enzymes involved in cholesterol synthesis
, C) By the concentration of cholesterol in the body
D) By the concentration of triacylglycerol in the body
E) Both A and B
Answer: E) Both A and B. Explanation: Cholesterol synthesis is regulated by the availability of
acetylCoA and the activity of the enzymes involved in cholesterol synthesis.
5. What is the contribution of cholesterol to the synthesis of steroid hormones?
A) Cholesterol is a precursor to steroid hormones
B) Cholesterol is a byproduct of steroid hormone synthesis
C) Cholesterol has no contribution to the synthesis of steroid hormones
D) Cholesterol inhibits the synthesis of steroid hormones
E) None of the above
Answer: A) Cholesterol is a precursor to steroid hormones. Explanation: Cholesterol is not only an
important component of membranes but also a precursor to steroid hormones.
1. Which of the following is true about phosphatidate?
a) It is a precursor of steroid hormones
b) It is synthesized from acetylCoA in four stages
c) It is a precursor of storage lipids and many membrane lipids
d) It is transported by lipoproteins throughout the body
e) It is tightly regulated at several levels
Answer: c) It is a precursor of storage lipids and many membrane lipids.
Explanation: Phosphatidate is a precursor of both storage lipids and many membrane lipids.
2. What is the common precursor for both triacylglycerol and phospholipids?
a) AcetylCoA
b) Cholesterol
c) Glycerol-3-P
d) Phosphatidate
e) Dihydroxyacetonephosphate
A) Fatty acids
B) Triacylglycerol
C) Phospholipids
D) Cholesterol
E) All of the above are discussed in this module
Answer: A) Fatty acids. Explanation: The previous module focused on the synthesis of fatty acids, while
this module focuses on the synthesis of three classes of lipids: triacylglycerol, phospholipids, and
cholesterol.
2. What is the precursor of both storage lipids and many membrane lipids?
A) Cholesterol
B) Triacylglycerol
C) Phosphatidate
D) AcetylCoA
E) None of the above
Answer: C) Phosphatidate. Explanation: Phosphatidate is a precursor of both storage lipids and many
membrane lipids.
3. How is cholesterol synthesized from acetylCoA?
A) Through a series of reactions involving enzymes and intermediates
B) Through a single-step reaction
C) Through a process of diffusion
D) Through a process of osmosis
E) None of the above
Answer: A) Through a series of reactions involving enzymes and intermediates. Explanation:
Cholesterol is synthesized from acetylCoA through a series of reactions involving enzymes and
intermediates.
4. How is cholesterol synthesis regulated?
A) By the availability of acetylCoA
B) By the activity of the enzymes involved in cholesterol synthesis
, C) By the concentration of cholesterol in the body
D) By the concentration of triacylglycerol in the body
E) Both A and B
Answer: E) Both A and B. Explanation: Cholesterol synthesis is regulated by the availability of
acetylCoA and the activity of the enzymes involved in cholesterol synthesis.
5. What is the contribution of cholesterol to the synthesis of steroid hormones?
A) Cholesterol is a precursor to steroid hormones
B) Cholesterol is a byproduct of steroid hormone synthesis
C) Cholesterol has no contribution to the synthesis of steroid hormones
D) Cholesterol inhibits the synthesis of steroid hormones
E) None of the above
Answer: A) Cholesterol is a precursor to steroid hormones. Explanation: Cholesterol is not only an
important component of membranes but also a precursor to steroid hormones.
1. Which of the following is true about phosphatidate?
a) It is a precursor of steroid hormones
b) It is synthesized from acetylCoA in four stages
c) It is a precursor of storage lipids and many membrane lipids
d) It is transported by lipoproteins throughout the body
e) It is tightly regulated at several levels
Answer: c) It is a precursor of storage lipids and many membrane lipids.
Explanation: Phosphatidate is a precursor of both storage lipids and many membrane lipids.
2. What is the common precursor for both triacylglycerol and phospholipids?
a) AcetylCoA
b) Cholesterol
c) Glycerol-3-P
d) Phosphatidate
e) Dihydroxyacetonephosphate
