Biomolecules - Organic Chemistry - Chemistry Previous Year Questions

Statement-1 : Glucose gives a reddish-brown precipitate with Fehling's solution.

Statement-2 : Reaction of glucose with Fehling's solution gives \(\mathrm{CuO}\) and gluconic acid.

Cellulose upon acetylation with excess acetic anhydride/H\(_2\)SO\(_4\) (catalytic) gives cellulose triacetate whose structure is :

The correct statement(s) about the following sugar X and Y is(are)

The total number of basic groups in the following form of lysine is

The correct statement about the following disaccharide is :

A decapeptide (mol. wt. 796) on complete hydrolysis gives glycine (mol. wt. 75), alanine and phenylalanine. Glycine contributes 47.0% to the total weight of the hydrolysed products. The number of glycine units present in the decapeptide is _________.

The following carbohydrate is

The substituents R₁ and R₂ for nine peptides are listed in the table given below. How many of these peptides are positively charged at pH = 7.0 ?

A tetrapeptide has \(-\)COOH group on alanine. This produces glycine (Gly), valine (Val), phenyl alanine (Phe) and alanine (Ala), on complete hydrolysis. For this tetrapeptide, the number of possible sequences (primary structures) with \(-\)NH₂ group attached to a chiral center is _______.

The structure of D-(+)-glucose is

The structure of L-(\(-\))-glucose is

For "invert sugar", the correct statement(s) is(are)

(Given : specific rotations of (+)-sucrose, (+)-maltose, L-(\(-\))-glucose and L-(+)-fructose in aqueous solution are +66\(^\circ\), +140\(^\circ\), \(-\)52\(^\circ\) and +92\(^\circ\), respectively.)

For a double strand DNA, one strand is given below:

The amount of energy required to split the double strand DNA into two single strands is _______ kcal $\operatorname{mol}^{-1}$.

[Given: Average energy per H-bond for A-T base pair $=1.0 ~\mathrm{kcal}~ \mathrm{mol}^{-1}$, G-C base pair $=1.5 ~\mathrm{kcal}$ $\mathrm{mol}^{-1}$, and A-U base pair $=1.25 ~\mathrm{kcal} ~\mathrm{mol}^{-1}$. Ignore electrostatic repulsion between the phosphate groups.]