Question

Give the salient features of the primary structure of a protein

Answer 1

Hint: We have studied that proteins are the polymers, of ${{\alpha }}$- amino acids, and they are connected with peptide bond or peptide linkage (-CO-NH-). They are broadly classified into two types
i. Fibrous proteins
ii. Globular proteins

Complete step by step solution:
To write the salient features we should first look at what does this primary structure of a protein means and to which group does it belong, from the above-mentioned ones’?

The structure of a protein can be classified into 4 different levels:
a) Primary
b) Secondary
c) Tertiary
d) Quaternary

The primary structure of a protein belongs to globular proteins. They may have one more polypeptide chain, which is formed by covalent bonds.
Salient features of the primary structure are;
The primary structure of a protein is a linear sequence of amino acid, with N- terminal on the first amino acid to the last C- terminal on the amino acid.,
The Primary structure of a protein does not say anything about the 3-dimension orientation of the protein. However, the shape of a protein depends on the information given by the primary protein, because it is the identity of the side chains and the sequence they are found in that determines how they will fold up in space.
The arrangements of the amino acids in the polypeptide chain, determine the action of a protein. Therefore, they are responsible for the biological action/or function of a protein. . Any alteration in the sequence of arrangement can lead to the change in the entire protein.
E.g., If the glutamic acid present in the 6th position of ${\text{\beta }}$the chain of hemoglobin (oxygen-carrying component in blood, also responsible for the red colour of the blood) is changed to Valine, the shape of the blood cell, from round changes to disk shape and the healthy cell converts into a sickle cell, which results in sickle cell anemia, which is an inherited disease.

Note: There might be chances of getting confused between the inability of the primary structural protein to predict the 3-dimension orientation of the protein, and the influence of the primary structure in the shape of the protein in space.