Q: ATP hydrolysis is often coupled to endergonic reactions in cells. Which equation best represents the hydrolysis of ATP?

$$\mathrm{ATP} + \mathrm{H}_2\mathrm{O} \rightarrow \mathrm{ADP} + \mathrm{P}_i + \text{energy}$$

Question 1

Which of the following best describes the difference between potential and kinetic energy in a biological context?

Accepted Answer

Potential energy is stored in chemical bonds, while kinetic energy is the energy of motion, such as muscle contractions.

Question 2

According to the first law of thermodynamics, which of the following equations correctly represents the conservation of energy in a closed system?

Accepted Answer

$$\Delta E = q + w$$

Question 3

A student claims that all the energy from food consumed by an animal is transferred to the next trophic level. Which law of thermodynamics explains why this is incorrect?

Accepted Answer

Second law, because some energy is always lost as heat, increasing entropy.

Question 4

Which of the following statements about exergonic reactions is correct?

Accepted Answer

The reaction proceeds with a net loss of free energy.

Question 5

ATP hydrolysis is often coupled to endergonic reactions in cells. Which equation best represents the hydrolysis of ATP?

Accepted Answer

$$\mathrm{ATP} + \mathrm{H}_2\mathrm{O} ightarrow \mathrm{ADP} + \mathrm{P}_i + 	ext{energy}$$

Question 6

Which of the following best explains how enzymes increase the rate of chemical reactions?

Accepted Answer

They lower the activation energy barrier, allowing more reactants to reach the transition state.

Question 7

A competitive inhibitor decreases the rate of an enzyme-catalyzed reaction by:

Accepted Answer

Binding to the active site, preventing substrate binding.

Question 8

Which of the following is a correct description of catabolic pathways?

Accepted Answer

They release energy by breaking down complex molecules into simpler ones.

Question 9

Which of the following statements about redox reactions is true?

Accepted Answer

Oxidation is the loss of electrons; reduction is the gain of electrons.

Question 10

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

Accepted Answer

Oxygen ($$\mathrm{O}_2)$$

Question 11

Which process produces the largest amount of ATP during aerobic cellular respiration?

Accepted Answer

Oxidative phosphorylation (ETC + chemiosmosis)

Question 12

Which of the following is NOT a function of the pentose phosphate pathway?

Accepted Answer

Generates ATP for anabolic pathways.

Question 13

Which of the following is a product of lactic acid fermentation?

Accepted Answer

Lactic acid

Question 14

Which of the following best describes the main function of the light reactions of photosynthesis?

Accepted Answer

Production of ATP and NADPH

Question 15

Where in a plant cell does the Calvin cycle take place?

Accepted Answer

Stroma

Question 16

Which of the following is a major difference between oxygenic and anoxygenic photosynthesis?

Accepted Answer

All of the above are major differences.

Question 17

Which of the following best explains why increasing substrate concentration can overcome competitive inhibition but not noncompetitive inhibition?

Accepted Answer

Competitive inhibitors bind to the active site, so more substrate can outcompete the inhibitor.

Question 18

Which of the following is the correct order of the stages of aerobic cellular respiration?

Accepted Answer

Glycolysis, pyruvate oxidation, Krebs cycle, electron transport chain & chemiosmosis

Question 19

Which of the following best describes the role of NADH and FADH2 in cellular respiration?

Accepted Answer

They shuttle electrons to the electron transport chain, where their energy is used to generate a proton gradient for ATP synthesis.

Microbial Metabolism: Principles, Pathways, and Energy Transformations

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