Question

Which one of the following is a conjugated protein?

• A. Phosphoprotein
• B. Glycoprotein
• C. Chromoprotein
• D. All of the above

Answer 1

Answer: (D)

Conjugated proteins on hydrolysis give a non protein portion alongwith $\alpha$-amino acid. The non-protein portion is called prosthetic group.

Protein	Prosthetic group
Phosphoprotein	Lipid (eg, lecithin)
Glycoprotein	Sugar
Chromoprotein	Colouring matter such as red coloured protophyrin

Since, all of them have non-protein part hence, all of them are conjugated protein.