Question

Which one is a simple protein?
A. Albumin
B. Nucleoprotein
C. Lipoprotein
D. Glycoprotein

Answer 1

Hint: Proteins are biopolymers made of repeating units of amino acids. Based on the chemical composition of proteins these are of two types. The proteins are made of amino acids arranged in different compositions that are unique to each protein type. Simple proteins consist of only amino acids but no other non-protein units.

Complete answer: Proteins are essential requirements of the body for proper functioning and maintenance of various metabolic processes. The proteins are composed of repeating units of amino acids. These amino acids are made in the cells of the body by codon on the genetic material. But the majority of essential amino acids are not made in the body and thus are required from dietary sources. So proteins are required by various protein-rich diets. The proteins are classified as simple and conjugated proteins based on their chemical composition. The simple proteins are those that are made of only amino acids. They do not consist of any other functional group or unit. On the other hand, the conjugated proteins as their name suggests are amino acids conjugated with some functional group units that impart them their characteristic properties. These conjugated units can be nucleic acids, lipids, glucose, etc. Albumin is a simple protein present in the transparent liquid found around the yolk of the egg. It is a globular protein having polar groups placed at the protein surface. Its composition consists of water and soluble proteins. On hydrolysis of albumin, only amino acids are obtained that proves that it is a simple protein.

Nucleoprotein, lipoprotein, and glycoprotein are conjugated proteins as they consist of amino acids conjugated with some functional groups or prosthetic groups. In nucleoprotein, the nucleic acid is the prosthetic group. In lipoprotein, the lipids are the prosthetic groups attached to amino acids. Lastly, in glycoprotein, glucose is the prosthetic group.
Therefore, Albumin is a simple protein and the right answer is option A.

Note: Inside the body, protein synthesis takes place by the process of translation. It involves the decoding of the mRNA that is made from the codon sequences of the DNA. This mRNA holds the information to make amino acids, in the cytoplasm, the tRNA and ribosomes conjugate to form translation machinery. They read the mRNA transcript and make amino acids that are then structured in chains to make proteins.