Question 1

Which of the following best describes the relationship between photosynthesis and cellular respiration in terms of their chemical equations?

Accepted Answer

The chemical equation for photosynthesis is the reverse of the equation for complete glucose breakdown in cellular respiration.

Question 2

During glycolysis, what is the net gain of ATP molecules per molecule of glucose, and why is this number not equal to the total ATP produced?

Accepted Answer

2 ATP, because 4 ATP are produced but 2 ATP are used during the energy investment stage.

Question 3

Which molecule acts as the final electron acceptor in the electron transport chain during aerobic cellular respiration?

Accepted Answer

Oxygen ($$O_2)$$

Question 4

A patient is exposed to cyanide, which inhibits enzymes in the electron transport chain. What immediate effect does this have on ATP production?

Accepted Answer

ATP production by chemiosmosis stops because the electron transport chain cannot function.

Question 5

Which of the following best explains why fats are considered the most efficient energy storage molecules in the human body?

Accepted Answer

Fatty acids are broken into 2-carbon units that enter cellular respiration as acetyl CoA, yielding more ATP per gram than carbohydrates or proteins.

Question 6

During intense exercise, muscle cells may switch to lactic acid fermentation. What is the primary reason for this metabolic shift?

Accepted Answer

Oxygen supply is insufficient for cellular respiration, so fermentation regenerates NAD+ to allow glycolysis to continue.

Question 7

Which of the following is a direct product of the Krebs cycle for each acetyl CoA that enters the cycle?

Accepted Answer

1 ATP, 3 NADH, 1 FADH2

Question 8

If a cell is deprived of oxygen, which of the following processes will stop first?

Accepted Answer

Electron transport chain

Question 9

Which of the following best describes chemiosmosis in mitochondria?

Accepted Answer

Hydrogen ions flow down their concentration gradient through ATP synthase, driving the synthesis of ATP from ADP and inorganic phosphate.

Question 10

Which of the following is a real-world application of mitochondrial DNA analysis, as discussed in the case study?

Accepted Answer

Identifying human remains, such as those of King Richard III, using mitochondrial DNA

Question 11

A yeast cell is placed in an anaerobic environment. Which metabolic pathway will it primarily use to generate ATP, and what are the end products?

Accepted Answer

Alcoholic fermentation; ethanol and carbon dioxide

Question 12

Which of the following equations correctly represents the complete breakdown of glucose during cellular respiration?

Accepted Answer

$$C_6H_{12}O_6$ + 6 O_2$ \rightarrow 6 CO_2$ + 6 H_2O + ATP~energy + heat$$

Question 13

Which of the following statements about substrate-level phosphorylation is correct?

Accepted Answer

It involves the direct transfer of a phosphate group from a substrate molecule to ADP to form ATP.

Question 14

Which of the following best explains why fermentation is important for cells under anaerobic conditions?

Accepted Answer

Fermentation regenerates NAD+ from NADH, allowing glycolysis to continue producing ATP.

Question 15

A person is on a low-carbohydrate, high-protein diet. Which metabolic pathway allows their body to use amino acids for energy?

Accepted Answer

Amino acids are deaminated and their carbon skeletons enter cellular respiration at various points, such as the Krebs cycle.

Question 16

Which of the following is a consequence if oxygen is not available to accept electrons at the end of the electron transport chain?

Accepted Answer

NADH and FADH2 cannot be oxidized, halting ATP production by chemiosmosis.

Question 17

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

Accepted Answer

They are released as carbon dioxide ($$CO_2) $$during the Krebs cycle and exhaled.

Question 18

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

Accepted Answer

Lactic acid fermentation produces lactate, while alcoholic fermentation produces ethanol and carbon dioxide.

Question 19

Which of the following statements about the location of cellular respiration processes is correct?

Accepted Answer

The Krebs cycle and electron transport chain occur in the mitochondria, while glycolysis occurs in the cytosol.

Harvesting Energy: Glycolysis and Cellular Respiration

Study Guide - Practice Questions