Question 1

Which of the following best explains how cholesterol affects membrane fluidity at different temperatures?

Accepted Answer

Cholesterol decreases membrane fluidity at high temperatures and increases it at low temperatures.

Question 2

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

Accepted Answer

The cell will burst because water moves in due to osmosis.

Question 3

Which of the following best describes the difference between simple diffusion and facilitated diffusion?

Accepted Answer

Facilitated diffusion requires a protein channel, while simple diffusion does not.

Question 4

Which of the following signaling types involves a cell releasing a signal that affects only nearby cells?

Accepted Answer

Paracrine signaling

Question 5

What is the main difference between exergonic and endergonic reactions in terms of free energy ($$\Delta G$$)?

Accepted Answer

Exergonic reactions have $$\Delta G  0.$$

Question 6

Which of the following statements about competitive inhibition is correct?

Accepted Answer

Competitive inhibitors increase $$K_m$$ but do not affect $$V_{max}.$$

Question 7

During cellular respiration, which molecule acts as the final electron acceptor in aerobic respiration?

Accepted Answer

O$$_2$$

Question 8

Which process directly produces the most ATP during cellular respiration?

Accepted Answer

Oxidative phosphorylation

Question 9

How does chemiosmosis in mitochondria differ from chemiosmosis in chloroplasts?

Accepted Answer

Protons accumulate in the intermembrane space in mitochondria and in the thylakoid lumen in chloroplasts.

Question 10

Which of the following best describes the role of Rubisco in photosynthesis?

Accepted Answer

Rubisco catalyzes the fixation of CO$$_2 to $$RuBP in the Calvin cycle.

Question 11

A plant cell is placed in a hypertonic solution. What will happen to the cell?

Accepted Answer

The cell will undergo plasmolysis as water leaves.

Question 12

Which of the following is true about substrate-level phosphorylation?

Accepted Answer

It directly transfers a phosphate group to ADP from a substrate.

Question 13

Which of the following best describes the difference between NAD	extsuperscript{+} and NADH?

Accepted Answer

NADH is the reduced form and carries electrons.

Question 14

Which of the following is a key difference between C$$_3$$, C$$_4$$, and CAM plants?

Accepted Answer

C$$_4$$ and CAM plants have adaptations to minimize photorespiration.

Question 15

Which of the following best describes the effect of a noncompetitive inhibitor on enzyme kinetics?

Accepted Answer

It does not affect $$K_m$$ but decreases $$V_{max}.$$

Question 16

Which of the following is true about the Calvin cycle?

Accepted Answer

It uses ATP and NADPH to fix CO$$_2$$ into carbohydrates.

Question 17

Which of the following best describes the difference between an electrical gradient and a concentration gradient?

Accepted Answer

An electrical gradient is based on charge differences, while a concentration gradient is based on solute amount differences.

Question 18

Which of the following is true about the electron transport chain in mitochondria?

Accepted Answer

It creates a proton gradient used by ATP synthase to generate ATP.

Question 19

Which of the following is a correct statement about G proteins in cell signaling?

Accepted Answer

G proteins relay signals from receptors to other proteins inside the cell.

Question 20

Which of the following best describes the effect of adding more substrate in the presence of a competitive inhibitor?

Accepted Answer

The inhibition can be overcome, and the reaction rate approaches $$V_{max}.$$

Analyzing Enzyme Activity Curves and Optimal Conditions

Study Guide - Practice Questions