Question 1

Which of the following best explains why amphipathic lipids spontaneously form bilayers in aqueous solution?

Accepted Answer

Because of the hydrophobic effect, which drives nonpolar tails away from water.

Question 2

Which structure is formed when amphipathic lipids aggregate in water and trap an aqueous compartment inside?

Accepted Answer

Liposome

Question 3

Biological membranes are described as a 'fluid mosaic.' Which of the following is NOT a component of this mosaic?

Accepted Answer

Trisaccharides

Question 4

Which of the following lipids would NOT be involved in forming a lipid bilayer structure?

Accepted Answer

Triacylglycerol

Question 5

Membrane components in a lipid bilayer are held together primarily by which type of interaction?

Accepted Answer

Hydrophobic interactions

Question 6

Which of the following statements about cholesterol in biological membranes is TRUE?

Accepted Answer

Cholesterol increases membrane fluidity at low temperatures.

Question 7

A mutation causes a cell to produce only single-tailed lipids. What structure would these lipids most likely form in water?

Accepted Answer

Micelle

Question 8

Which equation best represents the hydrophobic effect driving membrane formation?

Accepted Answer

$$\Delta G = \Delta H - T \Delta S$$

Question 9

Which of the following is a function of membrane proteins?

Accepted Answer

Facilitating transport of molecules across the membrane

Question 10

A researcher adds a detergent to a cell membrane. What is the most likely outcome?

Accepted Answer

The membrane will be disrupted as the detergent solubilizes the lipids.

Question 11

Which of the following best describes the arrangement of phospholipids in a bilayer?

Accepted Answer

Hydrophobic tails face inward, hydrophilic heads face outward.

Question 12

Which of the following is NOT a function of biological membranes?

Accepted Answer

Synthesizing ATP directly

Question 13

Which of the following would increase the fluidity of a biological membrane?

Accepted Answer

Increasing the proportion of unsaturated fatty acids

Question 14

Which of the following is a consequence of the fluid mosaic model of membranes?

Accepted Answer

Proteins and lipids can move laterally within the membrane.

Question 15

Which of the following best describes the role of sphingolipids in membranes?

Accepted Answer

They contribute to membrane structure and cell signaling.

Biological Membranes: Structure, Composition, and Properties

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