2.6 Study Guide

Question 1

Which of these fatty acids would have the lowest melting point?
a. 12:3
b. 14:3
c. 12:0
d. 14:0
e. 16:0

Answer 1

12:3

Question 2

You work at a lipid analysis lab and are performing a chemical analysis of the polar lipid head groups
from some membrane samples. You find that these head groups are composed of either one or two
galactose sugars. Which of these lipids do you suspect is present in the membrane of your cells?
a. Glycerophospholipids
b. Gangliosides
c. Sphingomyelins
d. Galactolipids
e. Cholesterol

Answer 2

Galactolipids

Question 3

For the class of lipids you identified in the previous questions, which of these other structural features
do they have?
1. Phosphate groups
2. Sphingosine
3. Glycerol
4. Ether linkages
5. Ester linkages

a. 1, 3, 5
b. 1, 2, 5
c. 2, 5
d. 3, 4
e. 3, 5

Answer 3

-Glycerol
-Ester linkages
3, 5

Question 4

Unfortunately some of the sample vials were poorly labeled and you need to match the results you
obtained in your initial analysis back to the most likely submitted sample. Of the following samples, from
which would you expect these results were most likely obtained?
a. Plant thylakoid membranes
b. Neural tissue
c. Archaea cultured from hot springs
d. Heart muscle cells
e. None of the above

Answer 4

Plant thylakoid membranes

Question 5

Which is TRUE about sphingosine?
a. It is a polar head group that contains sialic acid
b. It is amino alcohol with a long-chain fatty acid tail
c. It is found in Archaeal membranes
d. Two acyl tails are connected to it through amide linkages
e. All of the above

Answer 5

It is amino alcohol with a long-chain fatty acid tail

Question 6

Which of these lipids does not always have a sugar head group?
a. Glycerophospholipids
b. Gangliosides
c. Galactolipids
d. Cerebrosides
e. They all have sugar head groups

Answer 6

Glycerophospholipids

Question 7

You don’t know your blood type and decide to try to determine what it is through analysis of the
glycosphingolipids in your erythrocyte plasma membranes. You find that the head groups of these
glycosphingolipids have six sugars, with an extra galactose residue. What is your blood type likely to be?
a. A
b. B
c. O
d. AB
e. There is not enough information to make a guess

Answer 7

B

Question 8

Which is TRUE about lipids with a single acyl tail:
a. they are conical
b. they are cylindrical
c. they form vesicles
d. they form bilayers
e. all of the above

Answer 8

they are conical

Question 9

Which of the following membrane proteins moves phospholipids from the cytoplasmic leaflet of the
lipid bilayer to the outer leaflet?
a. Caveolin
b. Scramblase
c. Flippase
d. Floppase
e. None of these

Answer 9

Floppase

Question 10

You are studying bacteria to identify those that are particularly well-adapted to growing at warmer
temperatures in a bioreactor. Which of these bacteria would you expect to grow well at warmer
temperatures based on its membrane lipid profile?

          Strain A  Strain B  Strain C  14:0         40%    30%           35%  14:1         20%     30%          10%  16:0         30%     20%          40%  16:2         10%     20%           5% 

a. Strain A
b. Strain B
c. Strain C
d. They would all grow equally well

Answer 10

Strain C

Question 11

Hop diffusion describes:
a. Movement of a lipid between leaves of the bilayer
b. Movement of cholesterol in the membrane
c. Movement of a lipid within one microdomain before jumping to another
d. Movement of solutes through the membrane
e. None of the above

Answer 11

Movement of a lipid within one microdomain before jumping to another