Question 1

Which of the following best describes the relationship between photosynthesis and cellular respiration in plant cells?

Accepted Answer

Photosynthesis converts CO$$_2$$ and H$$_2O $$into organic molecules and O$$_2$$, while cellular respiration breaks down organic molecules using O$$_2 to $$produce CO$$_2$$, H$$_2O$$, and ATP.

Question 2

During cellular respiration, what is the primary role of oxygen (O$$_2$$)?

Accepted Answer

To accept electrons at the end of the electron transport chain, forming water.

Question 3

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

Accepted Answer

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

Question 4

What is the main purpose of NAD$$^+ in $$cellular respiration?

Accepted Answer

To shuttle electrons from food molecules to the electron transport chain by being reduced to NADH.

Question 5

Which stage of cellular respiration produces the most ATP?

Accepted Answer

Oxidative phosphorylation

Question 6

If a poison blocks the function of ATP synthase, which process would be directly affected?

Accepted Answer

The synthesis of ATP from ADP and inorganic phosphate during chemiosmosis

Question 7

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

Accepted Answer

Fats have more hydrogen atoms, providing more high-energy electrons for the electron transport chain.

Question 8

Which of the following is a correct sequence of events during aerobic cellular respiration?

Accepted Answer

Glycolysis → Pyruvate Oxidation → Citric Acid Cycle → Oxidative Phosphorylation

Question 9

A patient is diagnosed with a genetic disorder that prevents the recycling of NAD$$^+$$ during fermentation. What is the most likely consequence for their muscle cells during intense exercise?

Accepted Answer

Their muscle cells will be unable to produce ATP anaerobically, leading to rapid fatigue.

Question 10

Which of the following statements about feedback inhibition in cellular respiration is correct?

Accepted Answer

When ATP levels are high, an enzyme early in glycolysis is inhibited, slowing ATP production.

Question 11

Which of the following is a direct product of glycolysis?

Accepted Answer

Pyruvate

Question 12

What would happen to the process of oxidative phosphorylation if oxygen (O$$_2) $$were absent?

Accepted Answer

Electrons would not be able to move down the electron transport chain, and ATP synthesis would stop.

Question 13

Which of the following best describes the role of the citric acid cycle in cellular respiration?

Accepted Answer

It oxidizes acetyl CoA, producing NADH and FADH$$_2$$ for the electron transport chain.

Question 14

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

Accepted Answer

Alcoholic fermentation produces ethanol and CO$$_2$$, while lactic acid fermentation produces lactate and no CO$$_2.$$

Question 15

Which molecule is both an input and an output of glycolysis and the citric acid cycle, and is also involved in feedback inhibition?

Accepted Answer

ATP

Question 16

A person is fasting and their body begins to break down stored fats for energy. Which pathway do the fatty acids enter to be used for ATP production?

Accepted Answer

They are converted into acetyl CoA and enter the citric acid cycle.

Question 17

Which of the following statements about the energy yield of cellular respiration is correct?

Accepted Answer

About 34% of the energy in glucose is captured in ATP, with the rest released as heat.

Question 18

Which of the following best explains why glycolysis can occur in both aerobic and anaerobic conditions?

Accepted Answer

Glycolysis does not require oxygen and can regenerate NAD$$^+$$ through fermentation.

Cellular Respiration, Fermentation, and Photosynthesis: Energy Harvesting in Cells

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