Q: Which of the following equations correctly represents the net ATP yield from one molecule of glucose after all stages of aerobic cellular respiration?

$$\text{Net ATP} = 2 \ (\text{glycolysis}) + 2 \ (\text{Kreb’s cycle}) + 25 \ (\text{ETC}) = 29$$

Question 1

Which of the following best describes the main purpose of glycolysis in cellular respiration?

Accepted Answer

To convert glucose into two molecules of pyruvate, producing a net gain of 2 ATP and NADH.

Question 2

During the transition reaction (oxidative decarboxylation), which of the following occurs?

Accepted Answer

Pyruvate is converted into acetyl CoA, releasing $$CO_2 as a $$byproduct.

Question 3

Which stage of cellular respiration produces the greatest amount of ATP?

Accepted Answer

Electron Transport Chain and ATP Synthase

Question 4

A patient is diagnosed with a mitochondrial disorder that impairs the function of the inner mitochondrial membrane. Which process would be most directly affected?

Accepted Answer

Electron Transport Chain and ATP synthesis via ATP Synthase

Question 5

In the electron transport chain, what is the role of oxygen ($$O_2$$)?

Accepted Answer

It acts as the final electron acceptor, combining with protons to form water ($$H_2O).$$

Question 6

Which of the following equations correctly represents the net ATP yield from one molecule of glucose after all stages of aerobic cellular respiration?

Accepted Answer

$$	ext{Net ATP} = 2 \ (	ext{glycolysis}) + 2 \ (	ext{Kreb’s cycle}) + 25 \ (	ext{ETC}) = 29$$

Question 7

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

Accepted Answer

Glycolysis does not require oxygen and takes place in the cytosol.

Question 8

Which of the following is a direct output of the light-dependent reactions of photosynthesis?

Accepted Answer

ATP, NADPH, and $$O_2$$

Question 9

A plant is exposed to light but deprived of water. Which step in photosynthesis would be most directly affected?

Accepted Answer

Splitting of water to provide electrons in the light-dependent reactions

Question 10

Which of the following best describes the role of the proton gradient in the mitochondria during cellular respiration?

Accepted Answer

It drives the synthesis of ATP as protons flow through ATP Synthase.

Question 11

In the Calvin Cycle, which molecule is regenerated to allow the cycle to continue and acts as the initial acceptor of $$CO_2$$?

Accepted Answer

Ribulose-1,5-bisphosphate (RuBP)

Question 12

Which of the following scenarios would most likely result in a decrease in ATP production in a eukaryotic cell?

Accepted Answer

A mutation that impairs the function of ATP Synthase in the inner mitochondrial membrane

Question 13

Which of the following best explains why oxygen is essential for efficient ATP production in aerobic respiration?

Accepted Answer

Oxygen serves as the final electron acceptor in the electron transport chain, allowing the chain to continue functioning.

Question 14

A scientist measures the pH of the mitochondrial matrix and the intermembrane space during active respiration. Which of the following best describes the expected result?

Accepted Answer

The intermembrane space will have a lower pH (more acidic) than the matrix due to proton accumulation.

Question 15

Which of the following is a correct sequence of events in the light-dependent reactions of photosynthesis?

Accepted Answer

Absorption of light by Photosystem II $$\rightarrow$$ splitting of water $$\rightarrow$$ electron transport chain $$\rightarrow$$ formation of ATP and NADPH

Question 16

If a plant's thylakoid membranes are damaged, which process would be most directly impaired?

Accepted Answer

Production of ATP and NADPH during the light-dependent reactions

Question 17

Which of the following best describes the fate of the carbon atoms from glucose during aerobic cellular respiration?

Accepted Answer

They are released as $$CO_2$$ during the transition reaction and Kreb’s cycle.

Question 18

A mutation prevents NADP+ from being reduced to NADPH in the light-dependent reactions. Which process in the Calvin Cycle would be most directly affected?

Accepted Answer

Reduction of 3-phosphoglycerate to G3P

Question 19

Which of the following is a key difference between the electron transport chains in mitochondria and chloroplasts?

Accepted Answer

The mitochondrial chain uses $$O_2 as $$the final electron acceptor, while the chloroplast chain uses NADP+.

Question 20

Which of the following best explains why the Calvin Cycle is sometimes called the 'light-independent' reactions?

Accepted Answer

It does not require light directly and uses ATP and NADPH produced by the light-dependent reactions.

Cellular Respiration and Photosynthesis: Energy Pathways in Cells

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