Identify the basic amino acid.

Identify the protein present in nail.

$A$ tetrapeptide has a $-COOH$ group on alanine. This produces glycine $(Gly)$,valine $(Val)$,phenylalanine $(Phe)$,and alanine $(Ala)$ on complete hydrolysis. For this tetrapeptide,the number of possible sequences (primary structures) with the $-NH_2$ group attached to a chiral center is:

Can an enzyme be called a polymer?

Which of the following is not an essential amino acid?

How many amino acids are linked together by $(n-1)$ amide bonds?