Q: Which of the following equations correctly represents the ATP yield from the complete aerobic oxidation of one glucose molecule?

$$\text{Glucose} + 6\,\text{O}_2 \rightarrow 6\,\text{CO}_2 + 6\,\text{H}_2\text{O} + 32-34\,\text{ATP}$$

Question 1

Which of the following best describes the role of coenzymes such as NAD+ and FAD in cellular respiration?

Accepted Answer

They serve as hydrogen acceptors in redox reactions, becoming reduced to NADH and FADH2.

Question 2

During glycolysis, what is the net gain of ATP molecules produced per molecule of glucose, and what is the fate of pyruvate in the absence of oxygen?

Accepted Answer

Net gain is $$+2$$ ATP; pyruvate is reduced to lactic acid.

Question 3

Which process is responsible for the majority of ATP production during cellular respiration, and where does it occur?

Accepted Answer

Oxidative phosphorylation in the mitochondrial inner membrane

Question 4

A patient with uncontrolled diabetes mellitus is found to have a low blood pH. Which metabolic process is most directly responsible for this acidosis?

Accepted Answer

Excessive lipolysis leading to ketone body formation

Question 5

Which of the following equations correctly represents the ATP yield from the complete aerobic oxidation of one glucose molecule?

Accepted Answer

$$	ext{Glucose} + 6\,	ext{O}_2 ightarrow 6\,	ext{CO}_2 + 6\,	ext{H}_2	ext{O} + 32-34\,	ext{ATP}$$

Question 6

Which metabolic pathway allows the liver to maintain blood glucose levels during prolonged fasting by synthesizing glucose from non-carbohydrate sources?

Accepted Answer

Gluconeogenesis

Question 7

What is the primary fate of fatty acids released during lipolysis in a fasting individual?

Accepted Answer

They are converted into acetyl-CoA and enter the Krebs cycle.

Question 8

Which of the following best explains why insulin deficiency leads to hyperglycemia in diabetes mellitus?

Accepted Answer

Insulin deficiency increases glycogenolysis and uninhibited gluconeogenesis.

Question 9

Which process describes the conversion of amino acids into keto acids and ammonia, and what is the fate of ammonia in the body?

Accepted Answer

Deamination; ammonia is converted to urea and excreted by the kidneys.

Question 10

A person is experiencing hypoglycemia. Which metabolic process is most likely to be activated in the liver to restore blood glucose levels?

Accepted Answer

Glycogenolysis

Question 11

Which of the following is a cardinal sign of diabetes mellitus and is directly related to the osmotic effect of glucose in the renal tubules?

Accepted Answer

Polyuria

Question 12

Which of the following best describes substrate-level phosphorylation?

Accepted Answer

ATP is produced directly by transferring a phosphate group from a substrate to ADP.

Question 13

Which metabolic process is most likely to be upregulated in the liver during prolonged starvation, and what is its primary substrate?

Accepted Answer

Gluconeogenesis; amino acids

Question 14

What is the main reason excessive lipid catabolism can lead to ketoacidosis?

Accepted Answer

Incomplete oxidation of fatty acids leads to accumulation of ketone bodies.

Question 15

Which of the following statements about the Krebs cycle is correct?

Accepted Answer

It is O$$_2-$$independent and occurs in the mitochondrial matrix.

Question 16

Which process is responsible for the conversion of glucose to glycogen in the liver and muscle when glucose supplies exceed cellular needs?

Accepted Answer

Glycogenesis

Question 17

A patient is unable to efficiently use carbohydrates for energy due to a metabolic disorder. Which alternative metabolic pathway will be upregulated to provide ATP, and what is a potential risk of this shift?

Accepted Answer

Lipolysis; ketoacidosis

Question 18

Which of the following best explains why neurons are particularly dependent on glucose during hypoglycemia?

Accepted Answer

Neurons cannot use fatty acids efficiently and rely on glucose for ATP.

Question 19

Which of the following is a direct result of transamination in protein metabolism?

Accepted Answer

Generation of keto acids

Question 20

Which of the following best describes the chemiosmotic mechanism of ATP synthesis during oxidative phosphorylation?

Accepted Answer

ATP is synthesized as H+ ions flow down their gradient through ATP synthase.

Nutrition, Metabolism, and Body Temperature Regulation: Metabolic Pathways and Diabetes Mellitus

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