Question 1

Which of the following best describes the main function of the citric acid (Krebs) cycle in cellular metabolism?

Accepted Answer

To remove hydrogen atoms from organic molecules and transfer them to coenzymes such as NAD and FAD

Question 2

During prolonged fasting or starvation, which metabolic process increases most significantly to provide energy for the brain?

Accepted Answer

Ketogenesis

Question 3

Which of the following equations correctly represents the complete aerobic oxidation of glucose?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$} \rightarrow 36\ \mathrm{ATP} + 6\mathrm{CO_2$} + 6\mathrm{H_2O}$$

Question 4

A patient with a genetic defect in the enzyme phenylalanine hydroxylase will most likely develop which metabolic disorder?

Accepted Answer

Phenylketonuria (PKU)

Question 5

Which process is responsible for the synthesis of glucose from non-carbohydrate precursors such as amino acids and glycerol?

Accepted Answer

Gluconeogenesis

Question 6

Which of the following statements about oxidative phosphorylation is correct?

Accepted Answer

It generates ATP by transferring electrons from NADH and FADH2 to oxygen via the electron transport chain

Question 7

Which hormone is primarily responsible for stimulating glycogenolysis and gluconeogenesis during the postabsorptive state?

Accepted Answer

Glucagon

Question 8

What is the main fate of excess acetyl-CoA produced from beta-oxidation of fatty acids when carbohydrate intake is low?

Accepted Answer

It is converted to ketone bodies in the liver

Question 9

Which of the following best explains why proteins are not the body’s preferred energy source?

Accepted Answer

Proteins are more difficult to break apart, produce toxic byproducts, and are essential for structural and functional roles

Question 10

Which of the following mechanisms is the primary way the body loses heat during exercise in a hot, dry environment?

Accepted Answer

Evaporation

Question 11

A person with a high ratio of LDL to HDL cholesterol is at increased risk for which condition?

Accepted Answer

Atherosclerosis and cardiovascular disease

Question 12

Which of the following is a direct result of deamination of amino acids in the liver?

Accepted Answer

Formation of ammonium ions ($$\mathrm{NH_4$^+})$$

Question 13

Which of the following best describes the role of ATP synthase in the mitochondria?

Accepted Answer

It uses the energy of the proton gradient to synthesize ATP from ADP and inorganic phosphate

Question 14

Which of the following is a correct statement about the basal metabolic rate (BMR)?

Accepted Answer

BMR is the energy expended at rest to maintain vital body functions

Question 15

Which process is stimulated by insulin during the absorptive state?

Accepted Answer

Glycogenesis

Question 16

Which of the following best explains why the electron transport chain (ETC) requires oxygen?

Accepted Answer

Oxygen acts as the final electron acceptor, forming water

Question 17

Which of the following is a consequence of prolonged, uncontrolled ketosis?

Accepted Answer

Ketoacidosis, which can lead to coma and death

Question 18

Which of the following best describes the process of transamination?

Accepted Answer

The transfer of an amino group from an amino acid to a keto acid, forming a new amino acid

Question 19

Which of the following is the main reason why lipid catabolism yields more ATP per gram than carbohydrate catabolism?

Accepted Answer

Fatty acids have more hydrogen atoms, providing more electrons for the electron transport chain

Question 20

Which of the following is a primary effect of thyroid hormone on metabolism?

Accepted Answer

Increases the rate of energy use and heat production

Metabolism, Nutrition, and Energetics: Study Notes for Anatomy & Physiology

Study Guide - Practice Questions