Q: What is the primary source of energy released from ATP during cellular processes?

The hydrolysis of the terminal phosphate bond ($$\text{ATP} \rightarrow \text{ADP} + \text{P}_i)$$

Question 1

Which of the following statements best describes the relationship between catabolic reactions and entropy in biological systems?

Accepted Answer

Catabolic reactions increase entropy by breaking down molecules into simpler forms.

Question 2

Cellular respiration is an example of which type of reaction, and what is the sign of its $$\Delta G$$?

Accepted Answer

Exergonic reaction; $$\Delta G \u003c 0$$

Question 3

According to the first law of thermodynamics, which of the following is true about energy in biological systems?

Accepted Answer

Energy is transformed from one form to another but cannot be created or destroyed.

Question 4

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

Accepted Answer

Potential energy is stored in chemical bonds, kinetic energy is the movement of molecules, and chemical energy is the energy released during ATP hydrolysis.

Question 5

Enzymes catalyze reactions by:

Accepted Answer

Decreasing the activation energy ($$E_a) $$required for the reaction.

Question 6

Which of the following conditions is most likely to denature an enzyme and disrupt its function?

Accepted Answer

Drastically changing the pH away from the enzyme's optimum.

Question 7

A competitive inhibitor affects enzyme activity by:

Accepted Answer

Binding to the active site and preventing substrate binding.

Question 8

What is the primary source of energy released from ATP during cellular processes?

Accepted Answer

The hydrolysis of the terminal phosphate bond ($$	ext{ATP} ightarrow 	ext{ADP} + 	ext{P}_i)$$

Question 9

In the overall redox reaction of cellular respiration, which molecule is oxidized and which is reduced?

Accepted Answer

Glucose is oxidized; oxygen is reduced.

Question 10

Which stage of cellular respiration produces the most ATP, and where does it occur?

Accepted Answer

Electron transport chain and chemiosmosis; inner mitochondrial membrane

Question 11

During aerobic respiration, what is the final electron acceptor in the electron transport chain?

Accepted Answer

O$$_2$$

Question 12

Which of the following best explains why anaerobic respiration produces less ATP than aerobic respiration?

Accepted Answer

Anaerobic respiration relies on substrate-level phosphorylation and does not fully oxidize glucose.

Question 13

What is the main purpose of fermentation in cells?

Accepted Answer

To regenerate NAD$$^+ so $$glycolysis can continue.

Question 14

In photosynthesis, which molecule is reduced and which is oxidized in the overall reaction?

Accepted Answer

CO$$_2 is $$reduced; H$$_2O is $$oxidized.

Question 15

Which pigment is primarily responsible for absorbing light energy in photosynthesis, and what happens to wavelengths it does not absorb?

Accepted Answer

Chlorophyll; unabsorbed wavelengths are reflected, giving plants their green color.

Question 16

What is the main function of RUBISCO in the Calvin cycle?

Accepted Answer

To fix carbon by catalyzing the reaction between CO$$_2$$ and RuBP.

Question 17

Which of the following best describes the flow of electrons during the light reactions of photosynthesis?

Accepted Answer

Electrons flow from water to NADP$$^+$$ via photosystem II and photosystem I.

Question 18

Photorespiration is most likely to occur under which environmental condition, and what is its consequence for the plant?

Accepted Answer

High O$$_2$$ concentration and hot, dry conditions; decreased photosynthetic efficiency

Question 19

Which process is shared by both cellular respiration and photosynthesis, and what is its main function?

Accepted Answer

Chemiosmosis; to generate ATP using a proton gradient across a membrane

Cellular Respiration, Photosynthesis, and Enzyme Function: Core Concepts in Bioenergetics

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