Lipids & Membranes Revision Questions

Question 1

What are the components of a triglyceride molecule?

a) One glycerol and one cholesterol
b) One glycerol and two fatty acids
c) One cholesterol and two fatty acids
d) One glycerol and three fatty acids

Answer 1

d) one glycerol and three fatty acids

Question 2

Which of the following occurs after hydrogenation of a vegetable oil?
a) It will contain fewer trans double bonds and more double bonds in cis
conformation
b) It will become solid at room temperature and some double bonds might acquire
trans conformation
c) It will become polar with all double bonds in cis conformation
d) It will become a saturated fat with double bonds in trans conformation

Answer 2

b) It will become solid at room temperature and some double bonds might acquire
trans conformation

Question 3

Which of the following structures is a 20:2 (Δ4,9) fatty acid?

a) CH3(CH2)2CH = CH(CH2)3CH = CH(CH2)9COOH
b) CH3(CH2)9CH = CH(CH2)3CH = CH(CH2)2COOH
c) CH3(CH2)10CH = CH(CH2)3CH = CHCH2COOH
d) CH3CH2CH = CH(CH2)3CH = CH(CH2)10COOH

Answer 3

b) CH3(CH2)9CH = CH(CH2)3CH = CH(CH2)2COOH

Question 4

What term refers to a property of fatty acids of a phospholipid

a) hydrophobic
b) hydrophilic
c) amphipathic
d) polar

Answer 4

a) hydrophobic

Question 5

Biological waxes are composed of

a) Glycerol and one fatty acid
b) Glycerol and two fatty acids
c) Fatty acid and a long-chain alcohol
d) Fatty acid and cholesterol

Answer 5

c) fatty acid and a long-chain alcohol

Question 6

Which of the following statements are true about steroid hormones?

a) Are derivatives of cholesterol
b) Are less polar than cholesterol
c) Are paracrine hormones
d) Trigger gene expression
e) Are endocrine hormones

Answer 6

a) Are derivatives of cholesterol
d) Trigger gene expression
e) Are endocrine hormones

Question 7

Which is a characteristic of a sterol that is part of a cell membrane?

a) It contains a hydroxyl group
b) It contains four fused rings
c) It contains a phosphate group
d) It contains an amide bond

Answer 7

a) It contains a hydroxyl group

b) It contains four fused rings

Question 8

Which of the following helps maintain the structure of a cell membrane

a) Van der Waals interactions between phospholipid headgroups
b) H-bonds between fatty acids and polar headgroups
c) Hydrophobic effect promoted by fatty acid chains to avoid contact with water
d) H-bonds between fatty acids and water

Answer 8

c) Hydrophobic effect promoted by fatty acid chains to avoid contact with water

Question 9

Which best describes an integral protein

a) A protein attached to the surface of the cell
b) A protein within the cytoplasm
c) A protein anchored to a lipid
d) A protein embedded in the lipid membrane

Answer 9

d) A protein embedded in the lipid membrane

Question 10

Which is a characteristic of cell membranes?
a) Glycerophospholipids are distributed equally on the two lipid layers
b) Lipid molecules are held in fixed positions by non-covalent bonds with proteins
c) The fluidity of the membrane decreases with lower amounts of saturated fatty
acids.
d) The fatty acids of lipid molecules are found in the interior of the membrane

Answer 10

d) The fatty acids of lipid molecules are found in the interior of the membrane

Question 11

Which would be a property of all the major types of lipids in the membrane?

a) They are all apolar
b) They have polar heads and non-polar tails
c) They are composed of five-carbon units
d) They are joined to each other through covalent bonds

Answer 11

b) They have polar heads and non-polar tails