Questions and Ansẉers
2026\2027 update
1. Which of the following best describes a saturated fatty acid?
A) It contains one or more double bonds.
B) It contains only single bonds between carbon atoms.
C) It is always liquid at room temperature.
D) It contains a cyclic ring structure.
Answer: B
2. Naturally occurring unsaturated fatty acids typically have which
type of double bond configuration?
A) Trans
B) Cis
C) Conjugated
D) Triple
Answer: B
3. Which of the following are essential fatty acids that cannot be
synthesized by the human body?
A) Palmitic acid and stearic acid
B) Oleic acid and erucic acid
C) Linoleic acid and alpha-linolenic acid
,D) Arachidic acid and butyric acid
Answer: C
4. Triacylglycerols (triglycerides) are primarily used in the body for:
A) Cell membrane structure.
B) Long-term energy storage.
C) Enzyme catalysis.
D) Signaling and communication.
Answer: B
5. A glycerophospholipid consists of a glycerol backbone, two fatty
acids, and a:
A) Third fatty acid
B) Phosphate group linked to an alcohol
C) Sphingosine backbone
D) Carbohydrate moiety
Answer: B
6. Which of the following phospholipids is abundant in the myelin
sheath of nerve cells?
A) Phosphatidylcholine
B) Phosphatidylserine
C) Sphingomyelin
D) Phosphatidylglycerol
Answer: C
, 7. Cholesterol belongs to which class of lipids?
A) Phospholipids
B) Steroids
C) Prostaglandins
D) Triacylglycerols
Answer: B
8. The fluid mosaic model of cell membranes proposes that:
A) Membranes are rigid protein structures coated with lipids.
B) Membranes are a lipid bilayer with proteins embedded or
attached, capable of lateral movement.
C) Membranes consist of a single layer of lipids sandwiched between
proteins.
D) Membranes are composed entirely of carbohydrates.
Answer: B
9. How does cholesterol affect membrane fluidity at physiological
temperatures (e.g., 37°C)?
A) It increases fluidity by disrupting fatty acid packing.
B) It decreases fluidity by restricting the movement of fatty acid
tails.
C) It has no effect on membrane fluidity.
D) It solidifies the membrane completely.
Answer: B
10. Which of the following increases the fluidity of a cell membrane?