Chemistry - Biomolecules Question with Solution | TestHub

On treatment with phenylhydrazine, aldohexoses $\mathbf{P}$ and $\mathbf{Q}$ give the same osazone. On treatment with warm nitric acid, $\mathbf{P}$ gives an optically inactive aldaric acid, but sugar $\mathbf{Q}$ gives an optically active aldaric acid. Sugars $\mathbf{P}$ and $\mathbf{Q}$ are both degraded to aldopentose $\mathbf{R}$, which gives an optically active aldaric acid on treatment with nitric acid. Aldopentose $\mathbf{R}$ is degraded to aldotetrose $\mathbf{S}$, which gives optically active tartaric acid when it is treated with nitric acid. Aldotetrose $\mathbf{S}$ is degraded to $\mathbf{D}(+)$-glyceraldehyde. Identify correct structures of sugars ?