A hexapeptide has the composition `Ala,Gly,Phe,Val.` Both the `N-` terminal and `C-` teminal units are Val. Cleavage of the hexapeptide by chymotypsin gives two different tripeptides, both having Val as the N-terminal group. Among the products of random hydrolysis is a `Ala-Val` dipeptide fragment . What is the primary structure of the hexapeptide?

A tetrapeptide has -COOH group on alanine. This produces glycine (Gly), valine (Val), phenyl alanine (Phe) and alanine (Ala), on complete hydrolysis. For this tetrapeptide, the number of possible sequences (primary structures) with -NH_(2) group attached to a chiral centre is :

A tetrapeptide has -COOH group on alanine. This produces glycine (Gly), valine (Val), phenyl alanine (Phe) and alanine (Ala), on complete hydrolyses. For this tetrapeptide, the number of possible sequences (primary structures) with -NH_(2) group attached to a chiral centre is

Carbohydrates play a vital role in our daily life. These are classified as monosacchrides, oligosaccharides and polysaccharides depending upon the number of smaller molecules on hydrolysis. It has been suggested that monosaccharides do not have a free aldehyde or ketonic group but have cyclic hemiacetal or hemiketal structures. D - Glucose exists in two isomeric stereoisomeric forms : alpha-D- glucose and beta-D glucose which have different positions of H and OH groups on first carbon atom. Disaccharides such as sucuose, maltose, lactose, etc., give monosaccharides on hydrolysis. Polysaccharides are starch, cellulose, glycogen, having molecular formula (C_(6)H_(10)O_(5))_(n) . Name the water insoluble component of starch.