Question 1

Which of the following best explains why cells are limited in size?

Accepted Answer

As a cell increases in size, its volume increases faster than its surface area, limiting the rate of exchange with the environment.

Question 2

A scientist observes a cell with a large number of rough endoplasmic reticulum (RER). Which function is this cell most likely specialized for?

Accepted Answer

Synthesis of proteins for export out of the cell

Question 3

Which of the following statements correctly distinguishes between free and bound ribosomes?

Accepted Answer

Free ribosomes synthesize proteins that function in the cytosol, while bound ribosomes synthesize proteins destined for membranes or export.

Question 4

A mutation causes a plant cell to lack a primary cell wall. Which of the following is a likely consequence?

Accepted Answer

The cell will be more susceptible to bursting in hypotonic environments.

Question 5

Which cytoskeletal component is primarily responsible for the movement of cilia and flagella?

Accepted Answer

Microtubules

Question 6

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

Accepted Answer

A bilayer with hydrophilic heads facing outward and hydrophobic tails facing inward

Question 7

Which of the following molecules would most easily diffuse through a pure phospholipid bilayer?

Accepted Answer

Oxygen ($$O_2)$$

Question 8

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

Accepted Answer

The cell will swell and may burst due to water entering by osmosis.

Question 9

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

Accepted Answer

Active transport

Question 10

Which of the following best describes the role of cholesterol in the plasma membrane of animal cells?

Accepted Answer

It stabilizes membrane fluidity across temperature changes.

Question 11

A cell is observed to engulf large particles by wrapping its plasma membrane around them and forming a vesicle. This process is best described as:

Accepted Answer

Phagocytosis

Question 12

Which of the following statements about the Laws of Thermodynamics is correct as applied to living systems?

Accepted Answer

The total energy of a closed system remains constant, but energy transformations increase the entropy of the universe.

Question 13

Which of the following best describes the role of ATP in cellular metabolism?

Accepted Answer

ATP couples exergonic and endergonic reactions by providing free energy.

Question 14

Which of the following statements about enzyme function is correct?

Accepted Answer

Enzymes lower the activation energy barrier, increasing the rate of reaction.

Question 15

A metabolic pathway is regulated by feedback inhibition. Which of the following best describes this process?

Accepted Answer

The end product of the pathway inhibits an enzyme that acts early in the pathway.

Question 16

Which of the following is an example of energy coupling in cells?

Accepted Answer

The hydrolysis of ATP ($$ATP \rightarrow ADP + P_i) is $$used to drive the active transport of ions against their concentration gradient.

Question 17

Which of the following factors is most likely to decrease the rate of an enzyme-catalyzed reaction?

Accepted Answer

Adding a noncompetitive inhibitor

Question 18

A patient is given a drug that acts as a competitive inhibitor for a key metabolic enzyme. Which of the following best describes how this drug works?

Accepted Answer

It binds to the active site, preventing the substrate from binding.

Question 19

Which of the following best explains why plant cells do not burst in hypotonic solutions, while animal cells do?

Accepted Answer

Plant cells have a rigid cell wall that resists excessive water uptake.

Question 20

Which of the following best describes the induced fit model of enzyme function?

Accepted Answer

The enzyme changes shape slightly to better fit the substrate upon binding.

BSC2010 Exam #2 Study Guide: Chapters 6–8 (Cell Structure, Membrane Function, and Metabolism)

Study Guide - Practice Questions