$ATP \rightarrow ADP + P_i + \text{energy}$

Question 1

Which statement best describes the fluid mosaic model of the plasma membrane?

Accepted Answer

The membrane is a dynamic structure with diverse proteins embedded in a fluid phospholipid bilayer.

Question 2

A red blood cell placed in a hypertonic solution will:

Accepted Answer

Shrink as water leaves the cell to the higher solute concentration outside.

Question 3

Which type of membrane protein is responsible for relaying signals from outside the cell to the inside?

Accepted Answer

Receptor proteins

Question 4

Facilitated diffusion differs from simple diffusion in that facilitated diffusion:

Accepted Answer

Uses transport proteins to move polar or charged substances down their concentration gradient.

Question 5

Which equation correctly represents the hydrolysis of ATP?

Accepted Answer

$ATP ightarrow ADP + P_i + 	ext{energy}$

Question 6

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

Accepted Answer

Exocytosis

Question 7

According to the first law of thermodynamics, which statement is true?

Accepted Answer

Energy can change form but cannot be created or destroyed.

Question 8

Which of the following best describes an exergonic reaction?

Accepted Answer

A reaction that releases energy and yields products with less potential energy than the reactants.

Question 9

What is the main function of glycoproteins in the plasma membrane?

Accepted Answer

Serving as ID tags recognized by other cells.

Question 10

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Blocking substrate molecules from entering the active site.

Question 11

Which of the following is an example of active transport?

Accepted Answer

Pumping sodium ions out of a cell against their concentration gradient using ATP.

Question 12

Which process describes the diffusion of water across a selectively permeable membrane?

Accepted Answer

Osmosis

Question 13

If a plant cell is placed in an isotonic solution, what will happen?

Accepted Answer

The cell will become flaccid (limp).

Question 14

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

Accepted Answer

Storing genetic information.

Question 15

Which statement about enzyme catalysis is correct?

Accepted Answer

Enzymes lower the activation energy barrier, speeding up reactions.

Question 16

Which of the following best explains how ATP couples exergonic and endergonic reactions in the cell?

Accepted Answer

ATP is hydrolyzed to ADP and $P_i$, releasing energy that can be used to drive endergonic reactions.

Question 17

Which type of endocytosis involves the cell membrane wrapping around a particle to form a vacuole?

Accepted Answer

Phagocytosis

Question 18

Which of the following is a consequence of the second law of thermodynamics in biological systems?

Accepted Answer

Energy transfers or transformations increase disorder (entropy), with some energy lost as heat.

Question 19

Aquaporins are specialized membrane proteins that:

Accepted Answer

Facilitate rapid diffusion of water across the membrane.

Question 20

Which of the following would most likely result from a noncompetitive inhibitor binding to an enzyme?

Accepted Answer

The enzyme's shape changes, reducing its ability to bind the substrate.

Chapter 5: The Working Cell – Membrane Structure, Energy, and Enzymes

Study Guide - Practice Questions