
A tetrapeptide has group on alanine. The 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 group attached to a chiral centre is

Important Questions on Biomolecules



In alanylglycylleucylalanylvaline the number of peptide linkages is:


How many of the given compounds will give a positive Biuret test____?
Glycine, Glycylalanine, Tripeptide, Biuret







Following tetrapeptide can be represented as
( are one letter codes for amino acids)

Monomeric subunits of proteins can sometimes assemble into higher order assemblies. Two such related human proteins and assemble into hexamers by sequential assembly of their subunits. However, while assembles into a hexameric ring. assembles into a linear hexameric arrangement as shown in the figure. Only hexameric assemblies of the proteins are functional.
The equilibrium constants for association , and of subunits at each step until pentamers are assembled, both for and , are the same . However, the equilibrium association constant of the final step of assembly into a hexamer is drastically different, for and for . Based on this information, choose the statement(s) that is(are) likely to be true.







