Which amino acid from the following is $NOT$ synthesized in our body?

The helical structure of proteins is stabilized by

Haemoglobin is

At the isoelectric point,in which form does an amino acid exist?

Assume that a particular amino acid has an isoelectric point of $6.0$. In a solution at $pH$ $1.0$,which of the following species will predominate?

The number of $sp^2$ hybridised carbons present in "Aspartame" is