What are the products of the enzymatic hydrolysis of proteins?

Irreversible precipitation of proteins is called

The peptide that gives positive ceric ammonium nitrate and carbylamine tests is

Which of the following amino acids is optically inactive?

Identify the essential amino acids from below $:$
$(A)$ Valine
$(B)$ Proline
$(C)$ Lysine
$(D)$ Threonine
$(E)$ Tyrosine
Choose the correct answer from the options given below $:$

Peptide linkage is present in: