The correct structure of histidine in a strongly acidic solution $(\mathrm{pH}=2)$ is:

Consider the following sequence for aspartic acid:

The $\mathrm{pI}$ (isoelectric point) of aspartic acid is:

Analyse the following reactions and identify incorrect statements where $\mathrm{X}$ and $\mathrm{Y}$ are two different aldohexoses and $\mathrm{Z}$ is a ketohexoses.

Disaccharide $\left(\mathrm{A}\right)\stackrel{{\mathrm{H}}_2\mathrm{O}/{\mathrm{H}}^{+}}{\to }\mathrm{X}+\mathrm{Z}$

Disaccharide $\left(\mathrm{B}\right)\stackrel{{\mathrm{H}}_2\mathrm{O}/{\mathrm{H}}^{+}}{\to }2\mathrm{X}$

Disaccharide $\left(\mathrm{C}\right)\stackrel{{\mathrm{H}}_2\mathrm{O}/{\mathrm{H}}^{+}}{\to }\mathrm{X}+\mathrm{Y}$

(a) $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$ are reducing sugars.

(b) $\mathrm{B}$ and $\mathrm{C}$ have ${\mathrm{C}}_1-{\mathrm{C}}_4$ glycosidic linkage between two monosaccharide units.

(c)The two monosaccharide units of disaccharide 'C' are ${\mathrm{C}}_4$ epimers.

(d) All the three disaccharides undergo mutarotation.