Question 1

Which of the following best explains why unsaturated fats are typically liquids at room temperature?

Accepted Answer

They contain double bonds that create kinks, preventing tight packing of molecules.

Question 2

A patient has a genetic mutation that reduces the amount of cholesterol in their plasma membranes. Which of the following is the most likely effect on their cell membranes at high temperatures?

Accepted Answer

The membranes will become too fluid and more permeable.

Question 3

Which of the following statements about the Na/K pump is correct?

Accepted Answer

It moves 3 Na$^+$ ions out of the cell and 2 K$^+$ ions into the cell using ATP.

Question 4

Which type of transport is responsible for the movement of oxygen (O$_2$) across the plasma membrane?

Accepted Answer

Simple diffusion

Question 5

A cell is placed in a solution with a higher concentration of solutes than inside the cell. What process will occur, and what will be the direction of water movement?

Accepted Answer

Osmosis; water will move out of the cell.

Question 6

Which of the following best describes the role of phospholipids in the plasma membrane?

Accepted Answer

They form a bilayer that provides selective permeability and fluidity to the membrane.

Question 7

Which of the following molecules would most likely require a channel protein to cross the plasma membrane?

Accepted Answer

A charged ion such as Na$^+$

Question 8

Which process is used by cells to secrete large molecules, such as hormones, out of the cell?

Accepted Answer

Exocytosis

Question 9

A researcher observes that a certain molecule moves across the plasma membrane only when ATP is present. Which type of transport is most likely involved?

Accepted Answer

Active transport

Question 10

Which of the following statements about saturated fats is correct?

Accepted Answer

They have only single bonds between carbon atoms and are solid at room temperature.

Question 11

Which of the following best explains why phospholipids form bilayers in water?

Accepted Answer

Their hydrophilic heads interact with water while their hydrophobic tails avoid water.

Question 12

Which of the following is an example of receptor-mediated endocytosis?

Accepted Answer

A liver cell taking in LDL cholesterol from the bloodstream using specific membrane receptors.

Question 13

Which of the following best describes the effect of increasing temperature on membrane fluidity?

Accepted Answer

Membrane fluidity increases as temperature increases.

Question 14

A cell needs to import glucose, a large polar molecule, into its cytoplasm. Which transport mechanism is most likely used?

Accepted Answer

Facilitated diffusion via carrier proteins

Question 15

Which of the following is a property of steroids?

Accepted Answer

They have a characteristic four-ring structure and are classified as lipids.

Question 16

Which of the following best describes passive transport?

Accepted Answer

Movement of molecules down their concentration gradient without the use of ATP.

Question 17

A cell is observed to take in extracellular fluid and dissolved solutes by forming small vesicles. Which process is being observed?

Accepted Answer

Pinocytosis

Question 18

Which of the following would most likely increase the permeability of a plasma membrane?

Accepted Answer

Increasing the proportion of unsaturated fatty acids in phospholipids

Question 19

Which of the following is true about the movement of water across a selectively permeable membrane?

Accepted Answer

Water moves from areas of low solute concentration to areas of high solute concentration by osmosis.

Question 20

A cell is placed in a solution and swells until it bursts. Which of the following best explains this observation?

Accepted Answer

The solution is hypotonic to the cell, causing water to enter by osmosis.

Chapter 5 Study Guide: Lipids and Membrane Transport

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