PROTEIN

Which of the following is not a component of a basic amino acid structure?

• Amino group (–NH₂)

• Carboxyl group (–COOH)

• Phosphate group (–PO₄³⁻)

• Side chain (R group)

Answer explanation

Which protein structure level describes the sequence of amino acids in a polypeptide?

• Primary structure

• Secondary structure

• Tertiary structure

• Quaternary structure

Answer explanation

Secondary protein structures are stabilized mainly by hydrogen bonds between R groups.

• True
• False

Answer explanation

The function of protein depends on its tertiary structure (3D shape).

• True
• False

Answer explanation

Which type of bonds/interactions is the main stabilizing for subunits in quaternary structure?

• Hydrogen bonds

• Ionic bonds

• Hydrophobic interactions

• All of the above

Answer explanation