Question

The example of a protein is
a. Carvone
b. Lecithin
c. Cellulose
d. Insulin

Answer 1

Hint: Proteins are a chain of nucleic acids which are linked together by a peptide bond. In order to solve this question we need to remember that hormones are proteins in nature and we need to find a hormone among the four.

Complete Step by Step Solution:
Carvone- It contains ketone and two alkene functional groups. The chemical family of terpenoids includes carvone. Naturally occurring in numerous essential oils, carvone is most prevalent in the oils made from the seeds of dill, caraway, and spearmint (Mentha spicata). It’s a constituent in various oils and is not a protein.

Lecithin: An illustration of a phospholipid is lecithin. Probably the most prevalent phospholipid is lecithin. Choline, an amino alcohol, is present. It is obtained from soybeans and used as an emulsifying agent in food. It is present in soybeans, wheat germ, and egg yolks. The lipid bilayers of cell membrane also include a significant amount of lecithin. It’s not a protein.

Cellulose: The most prevalent organic polymer on earth is cellulose, a polysaccharide made up of a linear chain of $\beta (1\to 4)$linked d-glucose units with a degree of polymerization ranging from few hundreds to over ten thousand. It’s not a protein.
Insulin- Insulin is a hormone made up of protein composed of two chains: an $\alpha $chain with 21 amino acids and a \[\beta \]chain with 30 amino acids which are linked together by sulphur atoms. Insulin is derived from a 74 amino acid pro-hormone molecule called proinsulin.
So the correct option is D. insulin

Note: Remember the different categories of the biomolecules to which they belong. The hormones are intercellular messengers which are made up of proteins, so in these types of questions of protein identification, one must look for the option that contains the hormone.