Proteins are biomolecules composed of `alpha-` amino acids. An `alpha-`amino acid has a general formula `R-underset(underset(NH_(2))(|))(C)-COOH`. The amino acids polymerise and form an amide linkage (peptide linkage) between two monomeric amino acid units. The polymerisation takes place as follows
`H_(2)N-overset(overset(R_(1))(|))(CH)-underset(underset(O)(||))(C)-OH+H- underset(darr underset((-2H_(2)O))("Polymerisation"))(HN-overset(overset(R_(2))(|))(CH)-underset(underset(O)(||))(C))-OH+H-NH- overset(overset(R_(3))(|))(CH)-underset(underset(O)(||))(C)-OH`

Two or more similar amino acids can also polymerise, for example a dimer will be like.
`H_(2)N- overset(overset(R)(||))(CH)-underset(underset(O)(||))(C)-NH-overset(overset(R)(||))(CH)-underset(underset(O)(||))(C)-OH`.
Which statement is incorrect about the given trimer.

Options

A. it will liberated `CO_(2)` with `NaHCO_(3)`
B. it will liberate `N_(2)` with `NaNO_(2)//HCl`
C. It will give yellow precipitate with 2,4-Dinitrophenylhydrazine
D. It will rotate plane polarized light

Answer

C

Explanation

The trimer is chiral, it has free `COOH` group and free primary `NH_(2)` group, so statement `A,B,D` are correct. It does not have `C=O` group.