The acid showing salt-like character in aqueous solution is

Glycylalanine is a dipeptide of which amino acids?

The proteins with a prosthetic group are called

An amino acid may be represented by the general formula $H_2N-CH(R)-COOH$. If $R = -CH_2C_6H_5$,it is phenylalanine $(Phe)$,and if $R = -CH_3$,it is alanine $(Ala)$. Identify the correct reagents from the list below to synthesize the dipeptide $Phe-Ala$:
$(1) ZNH-CH(CH_3)-COOH$
$(2) H_2N-CH(CH_3)-COOCH_2C_6H_5$
$(3) ZNH-CH(CH_2C_6H_5)-COOH$
$(4) H_2N-CH(CH_2C_6H_5)-COOCH_2C_6H_5$
(Note: $Z$ represents the benzyloxycarbonyl protecting group).

The molecular weight of protein is

Assertion: $\alpha$-amino acids exist as internal salt in solution as they have amino and carboxylic acid groups in near vicinity.
Reason: $H^{+}$ ion given by carboxylic group $(-COOH)$ is captured by amino group $(-NH_2)$ having lone pair of electrons.