Question

Which one of the following is a conjugated protein?
A. phosphoprotein
B. glycoprotein
C. chromoprotein
D. all of these

Answer 1

We can identify the conjugated protein by checking the name of the protein. The conjugated protein has a prosthetic group. The prosthetic group is a non- polypeptide chemical group.

Complete answer:
The large structure made up of amino acids is known as protein or the simple protein. This protein on hydrolysis gives the amino acids but some protein on hydrolysis gives some chemical group that is non-polypeptides with the amino acids.
The protein in which a chemical group is attached by covalent bonding or other weak interaction and the group is necessary for the functioning of that protein is known as conjugated protein.
The non-polypeptide part of the conjugated protein is known as a prosthetic group.
The phosphoprotein has a non-polypeptide phosphate group. The phosphate group can be single phosphate or complex molecule such as DNA having phosphate so the phosphoprotein is a conjugated protein. So, option (A) is correct.
The glycoprotein has non-polypeptide oligosaccharides that are attached by covalent bonds, so the glycoprotein is a conjugated protein. So, option (B) is correct.
The chromoprotein has pigmented prosthetic groups such as heme in haemoglobin. The Heme group contains iron which binds with the oxygen molecule so the chromoprotein is a conjugated protein. So, option (C) is correct.

Therefore option (D) all of these, are correct.

Note: The chemical group that is attached with conjugated protein are non-polypeptide and the group is necessary for the functioning of the conjugated protein. The name of the conjugated protein has the name of the prosthetic group.