CPC CPC Biochemistry & Biological Chemistry

Question 1

Which bond type is primarily responsible for the secondary structure (α-helix and β-sheet) of proteins?

Accepted Answer

Hydrogen bonds between backbone NH and C=O groups

Answer

Disulfide bonds

Answer

Hydrophobic interactions

Answer

Ionic bonds between charged side chains

Question 2

In enzyme kinetics, the Michaelis constant (Km) represents:

Accepted Answer

Substrate concentration at which reaction velocity is half of Vmax

Answer

Maximum reaction velocity

Answer

Inhibitor concentration that halves enzyme activity

Answer

The equilibrium constant for enzyme-product formation

Question 3

Which nucleotide base pairs with adenine (A) in DNA?

Accepted Answer

Thymine (T)

Answer

Cytosine (C)

Answer

Guanine (G)

Answer

Uracil (U)

Question 4

The citric acid cycle (Krebs cycle) primarily occurs in which cellular compartment?

Accepted Answer

Mitochondrial matrix

Answer

Cytoplasm

Answer

Nucleus

Answer

Endoplasmic reticulum

Question 5

Which lipid class forms the basic structural component of biological cell membranes?

Accepted Answer

Phospholipids

Answer

Triglycerides

Answer

Sterols (cholesterol)

Answer

Waxes

Question 6

The Southern blot technique is used to detect:

Accepted Answer

Specific DNA sequences in a sample

Answer

Specific proteins in a mixture

Answer

RNA transcripts

Answer

Lipids in tissue extracts