Q: Which of the following equations correctly represents the overall process of cellular respiration?

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

Question 1

Which of the following best describes the relationship between photosynthesis and cellular respiration in an ecosystem?

Accepted Answer

Photosynthesis generates O2 and organic molecules, which are used in cellular respiration to produce ATP, CO2, and H2O.

Question 2

During aerobic cellular respiration, which molecule is oxidized and which is reduced?

Accepted Answer

Glucose is oxidized and O2 is reduced.

Question 3

Which of the following equations correctly represents the overall process of cellular respiration?

Accepted Answer

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

Question 4

Which of the following statements about glycolysis is TRUE?

Accepted Answer

Glycolysis breaks down glucose into two molecules of pyruvate and occurs in the cytoplasm.

Question 5

What is the primary function of NAD+ in cellular respiration?

Accepted Answer

To transfer electrons from organic molecules to the electron transport chain.

Question 6

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

Accepted Answer

Fermentation only uses glycolysis and does not utilize the citric acid cycle or oxidative phosphorylation.

Question 7

In the citric acid cycle, what is the fate of the carbon atoms from acetyl CoA?

Accepted Answer

They are released as CO2.

Question 8

Which of the following is a correct sequence of energy flow during cellular respiration?

Accepted Answer

glucose → NADH → electron transport chain → proton-motive force → ATP

Question 9

Which process is responsible for the majority of ATP produced during cellular respiration?

Accepted Answer

Oxidative phosphorylation

Question 10

What is the role of oxygen in the electron transport chain?

Accepted Answer

It acts as the final electron acceptor, forming water.

Question 11

Which of the following best describes chemiosmosis?

Accepted Answer

The use of a proton (H+) gradient across a membrane to drive the synthesis of ATP.

Question 12

A patient’s muscle cells are deprived of oxygen for an extended period. Which metabolic pathway will be primarily used to generate ATP, and what byproduct will accumulate?

Accepted Answer

Fermentation; lactic acid

Question 13

Which of the following statements about the conversion of pyruvate to acetyl CoA is correct?

Accepted Answer

It links glycolysis to the citric acid cycle and produces NADH and CO2.

Question 14

Which of the following is a key difference between lactic acid fermentation and alcohol fermentation?

Accepted Answer

Alcohol fermentation produces ethanol and CO2, while lactic acid fermentation produces lactate and no CO2.

Question 15

If a cell is unable to regenerate NAD+ during glycolysis, what will be the immediate consequence?

Accepted Answer

Glycolysis will stop, and ATP production will decrease.

Question 16

Which of the following best explains why fats yield more ATP per gram than carbohydrates?

Accepted Answer

Fats have more hydrogen atoms, leading to more electrons for the electron transport chain.

Question 17

A poison that blocks the passage of electrons along the electron transport chain will result in which of the following?

Accepted Answer

A decrease in the proton gradient across the inner mitochondrial membrane.

Question 18

Which of the following is the correct net equation for glycolysis?

Accepted Answer

$$ 	ext{C}_6	ext{H}_{12}	ext{O}_6 + 2 	ext{NAD}^+ + 2 	ext{ADP} + 2 	ext{P}_i ightarrow 2 	ext{Pyruvate} + 2 	ext{NADH} + 2 	ext{ATP} + 2 	ext{H}_2	ext{O} + 2 	ext{H}^+ $$

Question 19

Which of the following best describes the role of the proton-motive force in mitochondria?

Accepted Answer

It drives the synthesis of ATP by ATP synthase.

Question 20

A mutation prevents a cell from producing functional ATP synthase. Which of the following would be the most immediate effect?

Accepted Answer

The cell would be unable to produce ATP via oxidative phosphorylation.

Cellular Respiration and Fermentation: Mechanisms of Energy Harvest in Cells

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