M K Verma Solutions for Chapter: Biomolecules, Exercise 1: TOPICWISE QUESTIONS

Given: specific rotation of $(+)$ sucrose, $(+)$ maltose, $\mathrm{L}(-)$ glucose, $\mathrm{L}(+)$ fructose in aqueous, solution are $+66°,+140°,-52°$and$+92°$respectively. For 'invert sugar', the correct statements are?

(a) 'Invert sugar' is prepared by acid-catalyzed hydrolysis of maltose

(b) 'Invert sugar' is an equimolar mixture of $\mathrm{D}(+)$ glucose and $\mathrm{D}(-)$ fructose

(c) Specific rotation of  'invert sugar' is $(-20°)$

(d) On reaction with ${\mathrm{Br}}_2$ water ' invert sugar' forms saccharic acid as one of the products.

Lactose consists of:

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.

Which of the following is incorrect about sucrose?

Amino acids are classified as acidic, basic, or neutral depending upon the relative number of amino and carboxyl acid groups in their molecule. Which among the following are acidic?

Maltose consists of

Methyl  D-glucoside on reaction with ${\mathrm{HIO}}_4$ consumes two moles of the reagent and produces the dialdehyde  $$\begin{gathered} {\mathrm{HOCH}}_2-\mathrm{CH}-\mathrm{O}-\mathrm{CH}-{\mathrm{OCH}}_3 \\ | | \\ \mathrm{CHO} \mathrm{CHO} \end{gathered}$$ and one mole of $\mathrm{HCOOH}$. The result of this reaction proves that glucose has

Which of the following is not true for the structure (I) and (II)?