The total number of amino acids present in insulin is

The water-soluble protein is:

What is the number of amino acids present in a single turn of an $\alpha$-helix of a protein?

Which amino acid contains a secondary amino group in its structure?

Which amino acid does not contain a chiral centre?

Sulphur $(S)$ containing amino acids from the following are:
$(a)$ isoleucine
$(b)$ cysteine
$(c)$ lysine
$(d)$ methionine
$(e)$ glutamic acid