Question 1

Which of the following best describes the difference between potential energy and kinetic energy in a biological context?

Accepted Answer

Potential energy is stored energy, such as in chemical bonds, while kinetic energy is the energy of motion, such as a muscle contracting.

Question 2

A cell uses ATP to transport sodium ions against their concentration gradient. Which type of cellular work is being performed?

Accepted Answer

Transport work

Question 3

Which equation correctly represents the law of conservation of energy (First Law of Thermodynamics) as it applies to a biological system?

Accepted Answer

$$\Delta E = Q + W$$

Question 4

Which of the following best explains why entropy increases when energy is transferred in a cell?

Accepted Answer

Some energy is always lost as heat, increasing disorder in the system.

Question 5

A student reads that a 'food calorie' is actually a kilocalorie. Which of the following correctly relates these units?

Accepted Answer

1 food calorie = 1000 calories

Question 6

Which of the following best describes how ATP provides energy for cellular work?

Accepted Answer

ATP releases energy when its terminal phosphate group is removed by hydrolysis.

Question 7

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

Accepted Answer

Synthesizing DNA

Question 8

A scientist adds a competitive inhibitor to an enzyme reaction. What is the most likely effect?

Accepted Answer

The inhibitor binds to the active site, blocking substrate binding.

Question 9

Which process requires energy input from the cell and moves substances against their concentration gradient?

Accepted Answer

Active transport

Question 10

A red blood cell is placed in a hypotonic solution. What will most likely happen to the cell?

Accepted Answer

It will swell and may burst as water enters the cell.

Question 11

Which of the following best describes the relationship between osmosis and diffusion?

Accepted Answer

Osmosis is a type of diffusion that specifically involves water moving across a selectively permeable membrane.

Question 12

Which of the following scenarios illustrates the process of exocytosis?

Accepted Answer

A pancreatic cell releases insulin into the bloodstream.

Question 13

Which step is NOT part of the signal transduction pathway?

Accepted Answer

Replication of DNA

Question 14

Which of the following best explains how enzymes lower the activation energy of a reaction?

Accepted Answer

They provide a specific environment that stabilizes the transition state.

Question 15

A plant cell is placed in a hypertonic solution. What is the most likely outcome?

Accepted Answer

The cell will undergo plasmolysis as water leaves.

Question 16

Which of the following best describes facilitated diffusion?

Accepted Answer

Movement of molecules down their concentration gradient with the help of transport proteins, without energy input.

Question 17

Which equation best represents the hydrolysis of ATP?

Accepted Answer

$$\mathrm{ATP} + \mathrm{H}_2\mathrm{O} ightarrow \mathrm{ADP} + \mathrm{P_i} + 	ext{energy}$$

Question 18

Which of the following is an example of a noncompetitive inhibitor?

Accepted Answer

A molecule that binds to a site other than the active site, changing the enzyme's shape and reducing its activity.

Question 19

Which cellular structure is primarily responsible for controlling the flow of materials into and out of the cell?

Accepted Answer

Plasma membrane

Question 20

A patient is given an intravenous solution that is isotonic to their blood cells. What will happen to the cells?

Accepted Answer

The cells will remain unchanged.

Study Guide: The Working Cell (Chapter 5) – Key Concepts and Processes

Study Guide - Practice Questions