Question

Proteins are polymers of amino acids. Which of the following is not a protein?
A. wool
B. nail
C. hair
D. DNA

Answer 1

Hint: Nucleic acids are the organic biopolymers or large biomolecules that are essential to all the known forms of life. The term nucleic acid is the overall name for deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). They are composed of nucleotides (nucleoside + sugar), which are the monomers made of three components: a 5-carbon sugar molecule, a phosphate group and a nitrogenous base (thymine (in case of DNA), adenine cytosine, guanine or uracil (in case of RNA)).

Complete step by step answer:
Protein is an important nutrient needed by the human body for growth and maintenance. It is the last nutrient of the body after carbohydrate and fat that breaks down to release energy in the case of starvation. Aside from water, proteins are the next most abundant molecules in the human body and form the major part of the body. Proteins can be found in all the cells of the body and is the major structural component of all cells in the body, especially muscle. Inside a cell, a protein molecule is synthesized by the ribosomes. This also includes body organs, wool, hair and skin. The proteins that are generally found in wool, hair and nails are complex quaternary proteins. Wool, hair and nails are the exoskeletons made up of complex proteins. DNA is a nucleic acid and is not a protein, although it helps to build protein through the process of transcription and translation.

So, the correct answer is Option A .

Note:
Proteins are also used in membranes, such as glycoproteins. When broken down into amino acids, they are used as precursors to nucleic acid, coenzymes, hormones, immune response, cellular repair, and other molecules essential for life. Additionally, protein is needed to form blood cells also.