Question 1

Which of the following changes would most likely increase the permeability and fluidity of a cell membrane?

Accepted Answer

Increasing the proportion of phospholipids with short, unsaturated hydrocarbon tails

Question 2

Which molecule would diffuse most rapidly across a pure phospholipid bilayer?

Accepted Answer

Oxygen ($$O_2)$$

Question 3

Why do ions such as $$K^+$$ and $$Cl^-$$ have low permeability through the phospholipid bilayer?

Accepted Answer

Their hydration shells and charge make it energetically unfavorable to cross the hydrophobic core

Question 4

A protein that spans the membrane and has both hydrophobic and hydrophilic regions is best described as:

Accepted Answer

An amphipathic transmembrane protein

Question 5

Aquaporins are essential for:

Accepted Answer

Facilitating the rapid movement of water across cell membranes

Question 6

Which of the following best describes simple diffusion?

Accepted Answer

Movement of molecules down their concentration gradient without energy input

Question 7

In osmosis, water moves across a selectively permeable membrane:

Accepted Answer

From a region of lower solute concentration to higher solute concentration

Question 8

A plant cell placed in a hypotonic solution will:

Accepted Answer

Become turgid due to water entering the cell

Question 9

Which of the following is true about facilitated diffusion?

Accepted Answer

It uses transport proteins to move substances down their concentration gradient

Question 10

A carrier protein that moves two different solutes in opposite directions across a membrane is called a:

Accepted Answer

Antiporter

Question 11

Which of the following statements about active transport is correct?

Accepted Answer

It requires energy, often from ATP, to move solutes against their gradient

Question 12

The sodium-potassium pump ($$Na^+/K^+$$ ATPase) moves:

Accepted Answer

3 $$Na^+$$ out and 2 $$K^+ in $$per cycle

Question 13

Membrane potential is generated by:

Accepted Answer

The separation of positive and negative charges across the membrane

Question 14

Secondary active transport (cotransport) relies on:

Accepted Answer

A gradient established by primary active transport

Question 15

Which process allows a cell to engulf large particles, such as bacteria?

Accepted Answer

Phagocytosis

Question 16

A genetic defect in LDL receptor-mediated endocytosis can lead to:

Accepted Answer

Increased LDL levels in the blood

Question 17

Which of the following best describes the movement of water when a cell with $$0.03\ M$$ sucrose and $$0.02\ M$$ glucose is placed in an environment with $$0.01\ M$$ sucrose, $$0.01\ M$$ glucose, and $$0.01\ M$$ fructose?

Accepted Answer

Water will move into the cell, causing it to swell

Question 18

Which of the following is NOT a characteristic of channel proteins?

Accepted Answer

They undergo conformational changes to transport solutes

Question 19

Which of the following scenarios would most likely result in plasmolysis in a plant cell?

Accepted Answer

Placing the cell in a hypertonic solution

Question 20

Which of the following statements about exocytosis and endocytosis is correct?

Accepted Answer

Both processes require the formation of vesicles and energy input

Bio 100 LEC Chapter 7 Part 2

Study Guide - Practice Questions

Study Guide - Flashcards