Biology Test Biology Biochemistry & Metabolism 2

Question 1

The Krebs cycle occurs in which part of the mitochondria?

Accepted Answer

Matrix

Answer

The Krebs (citric acid) cycle takes place in the mitochondrial matrix where its enzymes are dissolved.

Question 2

Which type of bond links amino acids together in a protein?

Accepted Answer

Peptide bond

Answer

Peptide bonds form between the carboxyl group of one amino acid and the amino group of the next during protein synthesis.

Question 3

Beta-oxidation is the metabolic process that breaks down:

Accepted Answer

Fatty acids

Answer

Beta-oxidation sequentially cleaves two-carbon units from fatty acid chains, generating acetyl-CoA for the Krebs cycle.

Question 4

Competitive inhibition of an enzyme can be overcome by:

Accepted Answer

Increasing substrate concentration

Answer

In competitive inhibition, increasing substrate concentration outcompetes the inhibitor for the active site, restoring enzyme activity.

Question 5

Which vitamin is a precursor to the coenzyme NAD+?

Accepted Answer

Vitamin B3 (Niacin)

Answer

Niacin (vitamin B3) is the dietary precursor used by cells to synthesize NAD+ and NADP+.

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