IB DP Biology- B1.2 Proteins IB Style Questions For HL Paper 1-FA 2025

Question

Which row correctly matches the level of structure of a protein molecule with the bonds that stabilize it?

Option	Level of Structure	Bonds
A	primary	peptide and hydrogen bonds between amine and carboxyl groups
B	secondary	hydrogen bonds between R-groups of amino acids
C	tertiary	disulfide, hydrogen and ionic bonds between R-groups of amino acids
D	quaternary	covalent bonds between hydrophobic and hydrophilic regions on the polypeptide subunits

▶️ Answer/Explanation

The tertiary structure of a protein is stabilized by interactions between the R-groups (side chains) of amino acids. These include disulfide bridges (covalent), hydrogen bonds, ionic interactions, and hydrophobic forces, which give the protein its three-dimensional conformation.
✅ Answer: (C)

Question

Which of the following elements are constituents of proteins?

I. Carbon

II. Nitrogen

III. Oxygen

A. I only

B. I and II only

C. I and III only

D. I, II and III

▶️ Answer/Explanation

Solution

Proteins are organic macromolecules that contain several key elements.

The primary elements include Carbon (C), Nitrogen (N), and Oxygen (O).

Thus, all three elements (I, II, and III) are constituents of proteins.

✅ Answer: D. I, II and III

IB DP Biology- B1.2 Proteins IB Style Questions For HL Paper 1-FA 2025

Question

Resources

Members

Company