Question 1

Which of the following best describes the difference between anabolic and catabolic pathways in cellular metabolism?

Accepted Answer

Anabolic pathways consume energy to build complex molecules from simpler ones, while catabolic pathways release energy by breaking down complex molecules into simpler compounds.

Question 2

According to the first law of thermodynamics, which of the following statements is correct?

Accepted Answer

Energy can be transferred and transformed, but it cannot be created or destroyed.

Question 3

A cell is placed in a closed system and allowed to reach equilibrium. What will happen to the cell's metabolism?

Accepted Answer

The cell will die because metabolism requires a constant flow of materials and cannot occur at equilibrium.

Question 4

Which of the following equations correctly represents the change in free energy ($\Delta G$) for a chemical reaction?

Accepted Answer

$\Delta G = \Delta H - T\Delta S$

Question 5

Which of the following best explains why ATP is considered the cell's energy currency?

Accepted Answer

ATP hydrolysis releases energy that can be used to drive endergonic reactions by phosphorylation.

Question 6

During glycolysis, what are the net products formed from one molecule of glucose?

Accepted Answer

2 ATP, 2 NADH, and 2 pyruvate

Question 7

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes are macromolecules that speed up reactions by lowering the activation energy.

Question 8

A non-competitive inhibitor decreases the activity of an enzyme by:

Accepted Answer

Binding to another part of the enzyme, causing the enzyme to change shape and making the active site less effective.

Question 9

Which of the following best describes the role of NAD+ in cellular respiration?

Accepted Answer

NAD+ functions as an oxidizing agent, accepting electrons during the breakdown of glucose.

Question 10

In the electron transport chain, what is the primary function of the proton (H+) gradient across the inner mitochondrial membrane?

Accepted Answer

To drive the synthesis of ATP via chemiosmosis through ATP synthase.

Question 11

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

Accepted Answer

Glycolysis → Citric Acid Cycle → Electron Transport Chain

Question 12

Which of the following statements about fermentation is true?

Accepted Answer

Fermentation produces ATP only through substrate-level phosphorylation.

Question 13

During lactic acid fermentation, what is the fate of pyruvate?

Accepted Answer

Pyruvate is reduced by NADH to form lactate, with no release of CO$_2$.

Question 14

Which of the following best describes the chemiosmotic mechanism for ATP synthesis?

Accepted Answer

ATP is synthesized as protons flow down their electrochemical gradient through ATP synthase.

Question 15

Which of the following is a correct statement about the citric acid cycle?

Accepted Answer

The citric acid cycle completes the breakdown of pyruvate to CO$_2$ and generates NADH and FADH$_2$.

Question 16

Which of the following is a real-world example of an exergonic reaction in biology?

Accepted Answer

The hydrolysis of ATP to ADP and inorganic phosphate, releasing free energy.

Question 17

Which of the following best explains why feedback inhibition is important in metabolic pathways?

Accepted Answer

It prevents the overaccumulation of the end product by inhibiting an early enzyme in the pathway.

Question 18

Which of the following statements about autotrophs is correct?

Accepted Answer

Autotrophs sustain themselves without eating anything derived from other organisms.

Question 19

A scientist is studying a new enzyme and finds that its activity is highest at pH 2 and 37$^\circ$C. Which of the following is most likely true about this enzyme?

Accepted Answer

It is likely a digestive enzyme found in the human stomach.

Cellular Metabolism, Respiration, and Photosynthesis: Study Notes

Study Guide - Practice Questions

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