Question 1

Which of the following best explains why almost every intermediate in glycolysis contains a phosphate group?

Accepted Answer

Phosphate groups increase the solubility of intermediates, preventing them from diffusing out of the cell.

Question 2

During intense exercise, muscle cells convert pyruvate to lactate. What is the primary purpose of this conversion?

Accepted Answer

To regenerate NAD$$^+ so $$glycolysis can continue producing ATP under anaerobic conditions.

Question 3

Which of the following statements about insulin and glucagon is CORRECT?

Accepted Answer

Insulin promotes glycogenesis, while glucagon promotes glycogenolysis.

Question 4

Which of the following is a correct summary of the energy investment and energy generation phases of glycolysis?

Accepted Answer

The energy investment phase consumes 2 ATP, while the energy generation phase produces 4 ATP and 2 NADH.

Question 5

Which of the following best describes the fate of glycerol released during triacylglycerol mobilization in adipose tissue?

Accepted Answer

Glycerol is transported to the liver, where it can be converted to dihydroxyacetone phosphate (DHAP) and enter glycolysis or gluconeogenesis.

Question 6

Which of the following statements about β-oxidation is TRUE?

Accepted Answer

β-oxidation is a catabolic process that occurs in the mitochondria and produces acetyl-CoA, NADH, and FADH$$_2.$$

Question 7

Which of the following is a correct pairing of nucleic acid and its function?

Accepted Answer

tRNA: brings amino acids to the ribosome during translation

Question 8

A point mutation in DNA results in the codon $$	ext{GAA}$$ being changed to $$	ext{GUA}. $$What is the most likely consequence of this mutation?

Accepted Answer

A single amino acid substitution in the protein sequence

Question 9

Which of the following best describes the process of transamination?

Accepted Answer

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

Question 10

Which of the following amino acids is classified as both glucogenic and ketogenic?

Accepted Answer

Isoleucine

Question 11

During starvation, which metabolic pathway is most active in the liver to maintain blood glucose levels?

Accepted Answer

Gluconeogenesis

Question 12

Which of the following correctly matches a coenzyme with its role in metabolism?

Accepted Answer

NAD$$^+$$: accepts electrons during oxidation reactions such as glycolysis and the TCA cycle

Question 13

Which of the following is a direct product of ketogenesis in the liver?

Accepted Answer

Acetoacetate

Question 14

If a mutation causes the insertion of a single nucleotide into a coding region of DNA, what is the most likely result?

Accepted Answer

A frameshift mutation, altering the reading frame of the gene

Question 15

Which of the following best describes the role of the urea cycle?

Accepted Answer

To convert toxic ammonia into urea for excretion

Question 16

How many ATP equivalents are produced from the complete oxidation of one NADH molecule in the electron transport chain?

Accepted Answer

$$2.5$$

Question 17

Which of the following is a correct statement about DNA replication?

Accepted Answer

DNA replication is semiconservative, producing two DNA molecules each with one parental and one new strand.

Question 18

Which of the following best describes the connection between glycolysis and the TCA cycle?

Accepted Answer

Pyruvate, the end product of glycolysis, is converted to acetyl-CoA, which enters the TCA cycle.

Question 19

Which of the following is an example of a nonessential amino acid that can be synthesized from an essential amino acid?

Accepted Answer

Tyrosine from phenylalanine

Question 20

Which of the following best describes the process of translation?

Accepted Answer

The synthesis of a polypeptide chain from an mRNA template at the ribosome

Carbohydrate, Lipid, Nucleic Acid, and Protein Metabolism: Study Guide

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