$$6 \text{CO}_2 + 6 \text{H}_2\text{O} + \text{energy} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6 \text{O}_2$$

Question 1

Which of the following best describes the overall chemical equation for photosynthesis in plants?

Accepted Answer

$$6 	ext{CO}_2 + 6 	ext{H}_2	ext{O} + 	ext{energy} ightarrow 	ext{C}_6	ext{H}_{12}	ext{O}_6 + 6 	ext{O}_2$$

Question 2

Which statement best explains why the hydrolysis of ATP is considered an exergonic reaction?

Accepted Answer

It releases free energy, resulting in a negative $$\Delta G$$ value.

Question 3

Which of the following is the correct formula for calculating the change in free energy ($$\Delta G) $$for a chemical reaction?

Accepted Answer

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

Question 4

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

Accepted Answer

It acts as an oxidizing agent, accepting electrons and becoming reduced to NADH.

Question 5

Which process occurs in the mitochondria and is responsible for the majority of ATP production in aerobic organisms?

Accepted Answer

Electron transport chain and oxidative phosphorylation

Question 6

Which of the following statements about the citric acid cycle is TRUE?

Accepted Answer

It produces reduced coenzymes (NADH and FADH2) that carry electrons to the electron transport chain.

Question 7

Which of the following best describes the difference between catabolism and anabolism?

Accepted Answer

Catabolism breaks down molecules to release energy, while anabolism builds molecules and consumes energy.

Question 8

Which of the following reactions is most likely to be coupled with ATP hydrolysis to drive it forward?

Accepted Answer

A reaction with $$\Delta G = +5.0$$ kcal/mol

Question 9

Which of the following is a correct statement about the electron transport chain?

Accepted Answer

It creates a proton gradient across the inner mitochondrial membrane, which is used to synthesize ATP.

Question 10

Which of the following best explains why oxygen is essential for aerobic metabolism?

Accepted Answer

Oxygen acts as the final electron acceptor in the electron transport chain, allowing ATP production to continue.

Question 11

Which of the following is an example of an endergonic reaction?

Accepted Answer

Synthesis of glucose during photosynthesis ($$\Delta G \u003e 0)$$

Question 12

Which of the following best describes the function of coenzymes such as NADH and FADH2 in metabolism?

Accepted Answer

They act as electron carriers, transferring energy between metabolic pathways.

Question 13

Which of the following statements about ATP is FALSE?

Accepted Answer

ATP is the only molecule that can store energy in cells.

Question 14

Which of the following is a correct description of the role of enzymes in metabolic pathways?

Accepted Answer

Enzymes lower the activation energy of reactions, increasing the rate of metabolic processes.

Question 15

Which of the following best explains why the citric acid cycle is considered a 'cycle'?

Accepted Answer

The final product, oxaloacetate, is also the reactant for the first step.

Question 16

Which of the following is a direct product of the citric acid cycle that is immediately used to generate ATP in the electron transport chain?

Accepted Answer

NADH

Question 17

Which of the following best describes the fate of the acetyl group from acetyl-CoA in the citric acid cycle?

Accepted Answer

It is oxidized to CO2, and its electrons are transferred to NAD+ and FAD.

Question 18

Which of the following is a reason why energy must be released from food gradually in living organisms?

Accepted Answer

To prevent excessive heat production and allow controlled energy use for cellular processes.

Question 19

Which of the following statements about metabolic pathways is TRUE?

Accepted Answer

They consist of a series of enzyme-catalyzed reactions where the product of one reaction is the substrate for the next.

Question 20

Which of the following best describes the role of ATP synthase in the mitochondria?

Accepted Answer

It uses the energy from the proton gradient to phosphorylate ADP, forming ATP.

Chapter 21: The Generation of Biochemical Energy

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