BIOMOLECULES AND ENZYMES

Detailed explanation-1: -The -helix is one of the most common secondary structure motifs found in proteins and polypeptides and comprises a single strand of the polypeptide chain in a helical form with a right handed twist and is stabilized mainly by hydrogen bonds between C=Oi and N-Hi+4 groups within the same chain.

Detailed explanation-2: -An alpha helix is an element of secondary structure in which the amino acid chain is arranged in a spiral.

Detailed explanation-3: -An alpha helix is a type of secondary structure, i.e. a description of how the main chain of a protein is arranged in space. It is a repetitive regular secondary structure (just like the beta strand), i.e. all residues have similar conformation and hydrogen bonding, and it can be of arbitrary length.

Detailed explanation-4: -An helix is generated when a single polypeptide chain twists around on itself to form a rigid cylinder. A hydrogen bond is made between every fourth peptide bond, linking the C=O. of one peptide bond to the N–H of another (see Figure 3-9A).

Detailed explanation-5: -Reason for the name of alpha-helices: Amino acid chains frequently take the shape of an alpha helix. The fibrous protein alpha keratin is known to be the source of alpha-helices. Two alpha helices are twisted around each other in a coiled-coil structure in this protein.