Q: Which of the following equations correctly represents the overall reaction for aerobic cellular respiration?

$\mathrm{C_6H_{12}O_6} + 6\ \mathrm{O_2} \rightarrow 6\ \mathrm{CO_2} + 6\ \mathrm{H_2O} + \text{energy}$

Question 1

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

Accepted Answer

To break down glucose and other organic molecules to produce ATP for cellular work

Question 2

During glycolysis, what is the net gain of ATP and NADH molecules per molecule of glucose?

Accepted Answer

$2$ ATP and $2$ NADH

Question 3

Which of the following equations correctly represents the overall reaction for aerobic cellular respiration?

Accepted Answer

$\mathrm{C_6H_{12}O_6} + 6\ \mathrm{O_2} ightarrow 6\ \mathrm{CO_2} + 6\ \mathrm{H_2O} + 	ext{energy}$

Question 4

In the absence of oxygen, which process allows cells to continue producing ATP, and what is the main product in muscle cells?

Accepted Answer

Fermentation; lactic acid

Question 5

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

Accepted Answer

Oxygen ($\mathrm{O_2}$)

Question 6

A patient has a genetic defect that impairs the function of Complex IV in the electron transport chain. Which of the following would most likely occur as a result?

Accepted Answer

Decreased ATP production due to reduced proton gradient formation

Question 7

Which of the following best explains why NADH and FADH2 are important in cellular respiration?

Accepted Answer

They carry high-energy electrons to the electron transport chain for ATP production

Question 8

During the citric acid cycle, how many molecules of NADH are produced per turn of the cycle?

Accepted Answer

3

Question 9

Which step in glycolysis is considered the key regulatory step, and which enzyme catalyzes it?

Accepted Answer

Phosphofructokinase catalyzing the phosphorylation of fructose-6-phosphate

Question 10

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

Accepted Answer

Oxidative phosphorylation

Question 11

Which of the following statements about redox reactions in cellular respiration is correct?

Accepted Answer

Glucose is oxidized and oxygen is reduced

Question 12

A poison that blocks ATP synthase would directly prevent which process?

Accepted Answer

Chemiosmosis

Question 13

How many total ATP molecules (net) are produced from one molecule of glucose during aerobic respiration in eukaryotic cells?

Accepted Answer

About $30$ to $32$ ATP

Question 14

Which of the following best explains why fermentation is less efficient than aerobic respiration?

Accepted Answer

Fermentation does not use the electron transport chain, so less ATP is produced per glucose

Question 15

Which of the following is a correct sequence of events for the complete oxidation of glucose in cellular respiration?

Accepted Answer

Glycolysis $\rightarrow$ Pyruvate oxidation $\rightarrow$ Citric acid cycle $\rightarrow$ Oxidative phosphorylation

Question 16

A mutation causes a cell to lack the enzyme enolase. Which step of glycolysis would be directly affected?

Accepted Answer

Conversion of 2-phosphoglycerate to phosphoenolpyruvate

Question 17

Which of the following best describes substrate-level phosphorylation?

Accepted Answer

The direct transfer of a phosphate group from a substrate to ADP to form ATP

Question 18

In the citric acid cycle, which molecule combines with acetyl-CoA to form citrate?

Accepted Answer

Oxaloacetate

Question 19

If a cell is exposed to cyanide, which inhibits cytochrome c oxidase (Complex IV), what would be the immediate effect on the electron transport chain?

Accepted Answer

Electron flow would stop, halting ATP production by oxidative phosphorylation

Question 20

Which of the following is a real-life example of a situation where lactic acid fermentation occurs in human cells?

Accepted Answer

During intense exercise when oxygen supply to muscles is limited

Cellular Respiration: Pathways and Energy Yield

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