The helical structure of protein is stabilized by ..........

Which of the following tests cannot be used for identifying amino acids?

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.

Proteins are polymers of $\alpha$-amino acids,which are linked by peptide bonds. Chemically,proteins are:

Which one of the following statements is true for protein synthesis (translation)?

What type of bonding helps in stabilising the $\alpha$-helix structure of proteins?