The total number of negative charges in the tetrapeptide,$Gly-Glu-Asp-Tyr$,at $pH$ $12.5$ will be $......$ .

Identify the essential amino acids from the following:
$A$) Leucine
$B$) Tyrosine
$C$) Cysteine
$D$) Histidine

In a linear tetrapeptide (constituted with different amino acids),the value of (number of amino acids) - (number of peptide bonds) is:

The number of disulphide linkages present in insulin are

Which of the following statements is not correct?

In the primary structure of proteins,the amino acids are interconnected by-