What is the N and C terminal?

Hint: All proteins are macromolecules which have very high molecular weights. Chain-like molecules are produced by joining a number of small units of amino acids called monomers. As a result, amino acids are thought of as the "building blocks of proteins." Amino acids from protein through polymerization. An amino acid contains an amino group and a carboxylic group on the same carbon atom. Various kinds of amino acids include serine, arginine, glycine, and valine.

Complete Step by Step Solution:
A. Amino acid gets polymerized to form a peptide chain by the linkage of successive amino acids through peptide bonds. Peptide bond (-NH-CO-) is formed in between two amino acids by eliminating a water molecule.

B. The polarity of a polypeptide chain is due to its different polar terminal groups. In a polypeptide chain, one end contains an amino group (\[ - N{H_2}\] ) which is called the N-terminal, while the other end of the polypeptide chain contains a carboxyl group (−COOH) which is known as the C-terminal of the polypeptide chain.

Additional Information:
Free zwitterions of amino acids are present in the protoplasm. The sequence in which amino acids are arranged in a polypeptide chain of protein is known as the primary structure of the protein. A protein molecule usually has more than 100 amino acids in a polypeptide chain.

Note: Amino acids are classified as substituted methane because they include two end hydrogen atoms: one is replaced by an amino group and the other by a carboxylic group.
Each amino acid is amphoteric in nature because it contains one acidic (−COOH) and an alkaline group (\[ - N{H_2}\]).