Biomolecules — JEE Main PYQs

Identify the correct statements.

A. Arginine and Tryptophan are essential amino acids.
B. Histidine does not contain heterocyclic ring in its structure.
C. Proline is a six membered cyclic ring amino acid.
D. Glycine does not have chiral centre.
E. Cysteine has characteristic fe …

Given below are two statements:

Statement I: Sucrose is dextrorotatory. However sucrose upon hydrolysis gives a solution having mixture of products. This solution shows laevorotation.

Statement II : Hydrolysis of sucrose gives glucose and fructose. Since the laevorotation of gl …

The correct statements are:
A. Activation energy for enzyme catalysed hydrolysis of sucrose is lower than that of acid catalysed hydrolysis.
B. During denaturation, secondary and tertiary structures of a protein are destroyed but primary structure remains intact.
C. Nucleotides a …

Match List-I with List-II.

List-I
Reaction of glucose with
A. Hydroxylamine
B. ${\mathrm{Br}}_2$ water
C. Excess acetic anhydride
D. Concentrated ${\mathrm{HNO}}_3$

List-II
Product formed
I. Glouconic acid
II. Glucose pentacetate
III. Saccharic acid
IV. Glucoxime

Choose th …

Both human DNA and RNA are chiral molecules. The chirality in DNA and RNA arises due to the presence of

The number of possible tripeptides formed involving alanine (ala), glycine (gly) and valine (val), where no amino acid has been used more than once is :

In the given pentapeptide, find out an essential amino acid (Y) and the sequence present in the pentapeptide:

Choose the correct answer from the options given below:

Structures of four disaccharides are given below. Among the given disaccharides, the non-reducing sugar is :

Match List-I with List-II.

List-I (Vitamin):
A. Vitamin $B_1$
B. Vitamin $B_2$
C. Vitamin $B_6$
D. Vitamin C

List-II (Name):
I. Pyridoxine
II. Ascorbic acid
III. Thiamine
IV. Riboflavin

Choose the correct answer from the options given below:

Statement-I : The structure of Maltose is given below :

(structure shown)

Statement-II : The structure of Lactose is given below

(structure shown)

In the light of the above statements, choose the correct answer from the options given below

Match the LIST-I with LIST-II :

List-I Name of amino acid | List-II One letter symbol/type

Choose the correct answer from the options given below :

Identify the correct pair having amino acid (A) and the hormone (B) that is iodinated derivative of the amino acid (A).
( T and Y represent one letter code for amino acids)

A D-aldotetrose on oxidation with concentrated ${\mathrm{HNO}}_3$ resulted in optically inactive dicarboxylic acid. The structure of the D-aldotetrose is:

Identify the correct statements
A. Glucose exist in two anomeric forms.
B. Anomers of glucose differ in configuration at C -1 in cyclic hemiacetal structure.
C. Melting point of $\alpha$-anomer of glucose is greater than $\beta$-anomer.
D. Specific rotation of $\alpha$-anomer is …

Identify the incorrect statement about tertiary structure of proteins.

Given below are two statements :

Statement-I : (see structures) and (see structure) are two anomers of D-(+)-glucose.

Statement-II : The open chain forms of D-glucose and D-fructose contain three similar chiral carbons at C₃, C₄ and C₅.

In the light of the above statements, ch …

The incorrect statement from the following with respect to carbohydrates is :

Which of the following amino acid will give violet coloured complex with neutral ferric chloride solution?

Which of the following acids is a vitamin ?

Identify the number of structure/s from the following which can be correlated to D-glyceraldehyde.

The carbohydrates "Ribose" present in DNA, is
A. A pentose sugar
B. present in pyranose from
C. in "D" configuration
D. a reducing sugar, when free
E. in $\alpha$-anomeric form

Choose the correct answer from the options given below :

Match List-I with List-II.

List-I
(A) Adenine
(B) Cytosine
(C) Thymine
(D) Uracil

List-II
(I) (see structure)
(II) (see structure)
(III) (see structure)
(IV) (see structure)

Choose the correct answer from the options given below :

Given below are two statements:

Statement I: Fructose does not contain an aldehydic group but still reduces Tollen's reagent
Statement II: In the presence of base, fructose undergoes rearrangement to give glucose.
In the light of the above statements, choose the correct answer f …

Given below are two statements :

Statement I: D-glucose pentaacetate reacts with 2, 4-dinitrophenylhydrazine.
Statement II : Starch, on heating with concentrated sulfuric acid at $100^{\circ }\mathrm{C}$ and $2-3$ atmosphere pressure produces glucose.
In the light of the abo …

The $\alpha$-Helix and $\beta$-Pleated sheet structures of protein are associated with its:

Match List-I with List-II

List-I (Saccharides):
(A) Sucrose
(B) Maltose
(C) Lactose
(D) Amylopectin

List-II (Glycosidic-linkages found):
(I) $\alpha$ 1-4
(II) $\alpha 1-4$ and $\alpha 1-6$
(III) $\alpha 1-\beta 2$
(IV) $\beta 1-4$

Choose the correct answer from the o …

Identify correct conversion during acidic hydrolysis from the following :
(A) starch gives galactose.
(B) cane sugar gives equal amount of glucose and fructose.
(C) milk sugar gives glucose and galactose.
(D) amylopectin gives glucose and fructose.
(E) amylose gives only glucose. …

Match List - I with List - II.

Choose the correct answer form the options given below:

Identify the essential amino acids from below :
(A) Valine
(B) Proline
(C) Lysine
(D) Threonine
(E) Tyrosine

Choose the correct answer from the options given below:

Identify the correct statement among the following:

A tetrapeptide " $x$ " on complete hydrolysis produced glycine (Gly), alanine (Ala), valine (Val), leucine (Leu) in equimolar proportion each. The number of tetrapeptides (sequences) possible involving each of these amino acids is

Which of the following is the correct structure of L -fructose?

A dipeptide, "x" on complete hydrolysis gives "y" and "z". "y" on treatment with aq. ${\mathrm{HNO}}_2$ produces lactic acid. On the other hand "z" on heating gives the following cyclic molecule.

Based on the information given, the dipeptide X is:

Identify the pair of reactants that upon reaction, with elimination of HCl will give rise to the dipeptide Gly-Ala.

The total number of hydrogen bonds of a DNA-double Helix strand whose one strand has the following sequence of bases is ____.
5' - G - G - C - A - A - A - T - C - G - G - C - T - A - 3'

Given below are two statements :

Statement (I): On hydrolysis, oligo peptides give rise to fewer number of $\alpha$-amino acids while proteins give rise to a large number of $\beta$-amino acids.

Statement (II) : Natural proteins are denatured by acids which convert the water so …

Given below are two statements :

Statement I: D-(+)-glucose + D-(+) fructose $\stackrel{-{\mathrm{H}}_2\mathrm{O}}{\to }$ sucrose
sucrose $\stackrel{\text{ Hydrolysis }}{\to }$ D-(+)-glucose + D-(+) fructose
Statement II : Invert sugar is formed during sucrose hydrolysis.

In the lig …

(see structure)

Choose the correct option for structures of A and B, respectively.

Fat soluble vitamins are :
A. Vitamin ${\mathrm{B}}_1$
B. Vitamin C
C. Vitamin E
D. Vitamin ${\mathrm{B}}_{12}$
E. Vitamin K

Choose the correct answer from the options given below:

Which of the following is the correct structure of L-Glucose ?

Which of the following gives a positive test with ninhydrin?

Coagulation of egg, on heating is because of :

DNA molecule contains 4 bases whoes structure are shown below. One of the structure is not correct, identify the incorrect base structure.

The incorrect statements regarding enzymes are:
(A) Enzymes are biocatalysts.
(B) Enzymes are non-specific and can catalyse different kinds of reactions.
(C) Most Enzymes are globular proteins.
(D) Enzyme - oxidase catalyses the hydrolysis of maltose into glucose.
Choose the corr …

The total number of carbon atoms present in tyrosine, an amino acid, is ____ .

The incorrect statement regarding the given structure is

Total number of essential amino acid among the given list of amino acids is ____.
Arginine, Phenylalanine, Aspartic acid, Cysteine, Histidine, Valine, Proline

The incorrect statement about Glucose is :

Two nucleotides are joined together by a linkage known as :

The number of tripeptides formed by three different amino acids using each amino acid once is ____.