Question 1

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

Accepted Answer

Catabolic pathways break down complex molecules into simpler ones, releasing energy, while anabolic pathways build complex molecules from simpler ones, requiring energy input.

Question 2

A reaction has a negative Gibb’s free energy ($$\Delta G \u003c 0). $$Which of the following is true about this reaction?

Accepted Answer

The reaction is spontaneous and releases energy.

Question 3

Which of the following best explains why ATP is able to drive endergonic reactions in cells?

Accepted Answer

ATP hydrolysis releases energy by forming stronger bonds in ADP and phosphate, which can be coupled to endergonic reactions.

Question 4

Which of the following statements about enzyme inhibition is correct?

Accepted Answer

Competitive inhibition can be overcome by increasing substrate concentration, while noncompetitive inhibition cannot.

Question 5

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

Accepted Answer

Oxygen ($$O_2)$$

Question 6

Which process occurs in the cytosol of eukaryotic cells and does NOT require oxygen?

Accepted Answer

Glycolysis

Question 7

A patient’s muscle cells are deprived of oxygen during intense exercise. Which process allows these cells to continue producing ATP?

Accepted Answer

Lactic acid fermentation

Question 8

Which of the following best describes the role of the enzyme phosphofructokinase in glycolysis?

Accepted Answer

It acts as a key regulatory enzyme, controlling the rate of glycolysis through allosteric inhibition by ATP.

Question 9

Which of the following is a correct comparison between chemiosmosis in mitochondria and chloroplasts?

Accepted Answer

Both use a proton gradient to drive ATP synthesis via ATP synthase.

Question 10

Which of the following is true about the Calvin cycle?

Accepted Answer

It fixes carbon dioxide into organic molecules using ATP and NADPH.

Question 11

Why do C4 and CAM plants have adaptations for carbon fixation that differ from C3 plants?

Accepted Answer

To minimize photorespiration and conserve water in hot, dry environments.

Question 12

Which of the following best describes the function of receptor tyrosine kinases (RTKs) in cell signaling?

Accepted Answer

They dimerize and autophosphorylate upon ligand binding, initiating a phosphorylation cascade.

Question 13

Which of the following is an example of energy coupling in cellular metabolism?

Accepted Answer

The exergonic hydrolysis of ATP is used to drive the endergonic synthesis of glutamine from glutamate and ammonia.

Question 14

Which of the following best explains why an open system, such as a living cell, does not reach equilibrium?

Accepted Answer

Open systems constantly exchange energy and matter with their surroundings, preventing equilibrium.

Question 15

Which of the following is a correct description of the flow of electrons during photosynthesis?

Accepted Answer

Electrons flow from water to NADP+, forming NADPH.

Question 16

A scientist adds a competitive inhibitor to an enzyme-catalyzed reaction. Which of the following would most likely restore the reaction rate to normal?

Accepted Answer

Increasing the concentration of the substrate.

Question 17

Which of the following best describes the role of second messengers such as cyclic AMP ($$cAMP) in $$cell signaling?

Accepted Answer

They relay and amplify signals from receptors to target molecules inside the cell.

Question 18

Which of the following is a correct statement about the ATP yield from cellular respiration?

Accepted Answer

The exact number of ATP produced is variable due to differences in the efficiency of the electron transport chain and the use of the proton gradient for other processes.

Question 19

Which of the following best explains why photorespiration is considered wasteful for plants?

Accepted Answer

It consumes oxygen and releases carbon dioxide without producing ATP or sugar.

Question 20

Which of the following is a real-life example of lactic acid fermentation?

Accepted Answer

Production of yogurt by bacteria converting lactose to lactic acid.

General Biology I: Exam 3 Study Guide (Chapters 8–11) – Metabolism, Cellular Respiration, Photosynthesis, and Cell Communication

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