Which is an essential constituent of diet?

The isoelectric point of alanine is $pH = 6$. At which $pH$ will the maximum concentration of the zwitterion of alanine be present?

In fibrous proteins,the polypeptide chains are held together by.......

Thiol group is present in:

The artificial sweetener aspartame $(A)$,$H_3N^{+}-CH(CH_2COO^{-})-CONH-CH(CH_2Ph)-COOCH_3$,is converted to . . . . . . on storage for extended periods of time in aqueous solution:

$HC\equiv CH$ $\xrightarrow[HgSO_4]{H_2SO_4} (A)$ $\xrightarrow[(1) NH_3 + HCN]{(2) H_3O^{\oplus}} (B);$ The product $(B)$ of the given reaction is: