Q: Which equation correctly represents the change in free energy ($ riangle G$) for a chemical reaction?

$\triangle G = G_{final\ state} - G_{initial\ state}$

Q: Which of the following best describes the difference between exergonic and endergonic reactions?

Exergonic reactions have a negative $\triangle G$ and are spontaneous, while endergonic reactions have a positive $\triangle G$ and are nonspontaneous.

Question 1

Which of the following statements best describes the role of cholesterol in the plasma membrane, as shown in the diagram?

Accepted Answer

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

Question 2

A mutation causes the hydrophobic region of an integral protein to contain polar amino acids instead of nonpolar ones. What is the most likely consequence for the protein's function?

Accepted Answer

The protein may not properly embed in the membrane, disrupting its function.

Question 3

Which of the following molecules can most easily diffuse through the lipid bilayer without the aid of a transport protein?

Accepted Answer

Oxygen ($O_2$)

Question 4

A cell is placed in a hypertonic solution. What will happen to the cell, and why?

Accepted Answer

The cell will lose water and shrink because water moves from an area of higher concentration inside the cell to lower concentration outside.

Question 5

Which type of membrane protein is most likely to be involved in cell signaling and why?

Accepted Answer

Integral proteins, because they span the membrane and can transmit signals from outside to inside the cell.

Question 6

Which equation correctly represents the change in free energy ($	riangle G$) for a chemical reaction?

Accepted Answer

$	riangle G = G_{final\ state} - G_{initial\ state}$

Question 7

Which of the following best describes the difference between exergonic and endergonic reactions?

Accepted Answer

Exergonic reactions have a negative $	riangle G$ and are spontaneous, while endergonic reactions have a positive $	riangle G$ and are nonspontaneous.

Question 8

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to the active site and preventing substrate binding.

Question 9

During cellular respiration, which stage produces the most ATP?

Accepted Answer

Oxidative phosphorylation

Question 10

Which of the following is true about redox reactions in cellular respiration?

Accepted Answer

Oxidation involves the loss of electrons, while reduction involves the gain of electrons.

Question 11

Which of the following best explains why enzymes lower the activation energy ($E_a$) of a reaction?

Accepted Answer

Enzymes stabilize the transition state, making it easier for reactants to reach the product state.

Question 12

Which of the following is a real-world example of feedback inhibition?

Accepted Answer

The end product of a metabolic pathway binds to an enzyme early in the pathway, decreasing its activity.

Question 13

In the electron transport chain, what is the role of oxygen?

Accepted Answer

Oxygen acts as the final electron acceptor, forming water.

Question 14

Which process in photosynthesis directly generates ATP?

Accepted Answer

Photophosphorylation during the light reactions

Question 15

A patient is exposed to a pesticide that acts as a noncompetitive inhibitor of a key metabolic enzyme. What is the most likely effect?

Accepted Answer

The enzyme's active site changes shape, reducing its activity regardless of substrate concentration.

Question 16

Which of the following best describes the movement of protons during ATP synthesis in mitochondria?

Accepted Answer

Protons are pumped into the intermembrane space and diffuse back into the mitochondrial matrix through ATP synthase.

Question 17

Which of the following is a correct sequence of events in cellular respiration?

Accepted Answer

Glycolysis → Citric acid cycle → Oxidative phosphorylation

Question 18

Which of the following best explains why glucose cannot easily cross the plasma membrane without a transport protein?

Accepted Answer

Glucose is a large, polar molecule and cannot pass through the hydrophobic core of the lipid bilayer.

Question 19

Which of the following is true about the orientation of glycoproteins and glycolipids in the plasma membrane?

Accepted Answer

They are found on the extracellular side of the membrane and play a role in cell recognition.

Cell Membranes, Transport, and Cellular Metabolism: Study Notes for General Biology

Study Guide - Practice Questions

Study Guide - Flashcards