Protein (Part-II)

Summary of Previous Lecture: In the previous we discussed several aspect of amino acids, the building block of proteins. Now in the current lecture, we will discuss more about the protein structure and its function.

Structure of protein-As disussed in previous lecture, Protein is made up of 20 naturally occurring amino acids. A typical amino acid contains a amino and a carboxyl group attached to the central α-carbon atom (Figure 33.1). The side chain attached to the α-central carbon atom determines the chemical nature of different amino acids. Peptide bonds connect individual amino acids in a polypeptide chain. Each amino acid is linked to the neighboring amino acid through a acid amide bond between carboxyl group and amino group of the next amino acid. Every polypeptide chain has a free N- and C-terminals (Figure 33.1). Primary structure of a protein is defined as the amino acid sequence from N- to the C-terminus with a length of several hundred amino acids.

Figure 38.3: The connection between two adjacent amino acids in a polypeptide.