$$\text{Water moves from regions of low solute concentration to regions of high solute concentration}$$

Question 1

Which of the following is a common feature shared by all lipids?

Accepted Answer

They are insoluble in water due to their hydrophobic properties.

Question 2

Why do saturated fatty acids with long hydrocarbon tails tend to be solid at room temperature?

Accepted Answer

Their straight tails allow tight packing, increasing van der Waals interactions.

Question 3

Fats store more energy than carbohydrates because:

Accepted Answer

Fats have more C-H bonds, which release more energy when oxidized.

Question 4

Which of the following best describes the structure of a phospholipid?

Accepted Answer

A hydrophilic head and two hydrophobic tails.

Question 5

What is the primary role of cholesterol in animal cell membranes?

Accepted Answer

To regulate membrane fluidity.

Question 6

Which of the following molecules would most easily cross a pure phospholipid bilayer by simple diffusion?

Accepted Answer

O$$_2$$

Question 7

A cell is placed in a solution that is hypertonic to its cytoplasm. What will happen to the cell?

Accepted Answer

Water will move out of the cell, causing it to shrink.

Question 8

Which of the following statements about passive transport is correct?

Accepted Answer

It involves the net movement of solutes from high to low concentration.

Question 9

Facilitated diffusion differs from simple diffusion in that:

Accepted Answer

Facilitated diffusion uses membrane proteins to transport molecules.

Question 10

The sodium-potassium pump is an example of:

Accepted Answer

Primary active transport

Question 11

Which equation best represents the net movement of water during osmosis?

Accepted Answer

$$	ext{Water moves from regions of low solute concentration to regions of high solute concentration}$$

Question 12

Which of the following would increase the permeability of a cell membrane?

Accepted Answer

Increasing the number of unsaturated fatty acids in phospholipids

Question 13

A carrier protein such as GLUT-1 facilitates the movement of glucose across the membrane by:

Accepted Answer

Changing its shape to transport glucose down its concentration gradient

Question 14

Secondary active transport (co-transport) relies on:

Accepted Answer

Electrochemical gradients established by primary active transport

Question 15

Which of the following is NOT a function of membrane proteins?

Accepted Answer

Synthesizing phospholipids for the membrane

Question 16

If a cell membrane is composed mainly of saturated fatty acids, what effect does this have on the membrane?

Accepted Answer

It decreases membrane permeability.

Question 17

Which of the following best explains why ions such as Na$$^+$$ and K$$^+$$ cannot cross the lipid bilayer by simple diffusion?

Accepted Answer

They are charged and interact unfavorably with the hydrophobic core.

Question 18

Which of the following scenarios would result in no net movement of water across a cell membrane?

Accepted Answer

The cell is in an isotonic solution.

Question 19

What is the main difference between channel proteins and carrier proteins in membrane transport?

Accepted Answer

Channel proteins form open pores, while carrier proteins undergo conformational changes.

Lipids, Membranes, and Membrane Transport

Study Guide - Practice Questions