$A$ peptide synthesized by the reactions of one molecule each of Glycine,Leucine,Aspartic acid and Histidine will have ..... peptide linkages.

The following tetrapeptide can be represented as:
($F, L, D, Y, I, Q, P$ are one-letter codes for amino acids)

Amino acids are produced on hydrolysis of:

Out of the following,which type of interaction is responsible for the stabilisation of $\alpha$-helix structure of proteins?

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).

Lysine is least soluble in water in the $pH$ range: