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JEE Main

Explore popular questions from Biomolecules for JEE Main. This collection covers Biomolecules previous year JEE Main questions hand picked by experienced teachers.

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Biomolecules

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Q 1. An {tex} \alpha {/tex} -helix is a structure feature of:

Polypeptides

B

Polyethylene

C

Cellulose

D

Rubber

Explanation

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Q 2. RNA and DNA are chiral molecules, their chirality is due to:

D-sugar compound

B

L-sugar component

C

chiral bases

D

Chiral phosphate ester groups

Explanation

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Q 3. In both {tex}\mathrm{DNA}{/tex} and {tex}\mathrm{RNA}{/tex}, heterocyclic base and phosphate ester linkages are at

A

{tex} \mathrm { C } _ { 5 } ^ { \prime } {/tex} and {tex} \mathrm { C } _ { 2 } ^ { \prime } {/tex} respectively of the sugar molecule

B

{tex} \mathrm { C } _ { 2 } ^ { \prime } {/tex} and {tex} \mathrm { C } _ { 5 } ^ { \prime } {/tex} respectively of the sugar molecule

{tex} \mathrm { C } _ { 1 } ^ { \prime } {/tex} and {tex} \mathrm { C } _ { 5 } ^ { \prime } {/tex} respectively of the sugar molecule

D

{tex} \mathrm { C } _ { 5 } ^ { \prime } {/tex} and {tex} \mathrm { C } _ { 1 } ^ { \prime } {/tex} respectively of the sugar molecule

Explanation

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Q 4. The pyrimidine bases present in {tex}\mathrm{DNA}{/tex} are

A

cytosine and adenine

B

cytosine and guanine

cytosine and thymine

D

cytosine and uracil.

Explanation


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Q 5. The term anomers of glucose refers to

A

isomers of glucose that differ in configurations at carbons one and four {tex} ( \mathrm { C } - 1 \text { and } \mathrm { C } - 4 ) {/tex}

B

a mixture of {tex}(\mathrm D){/tex}-glucose and {tex}(\mathrm L){/tex}-glucose

C

enantiomers of glucose

isomers of glucose that differ in configuration at carbon one {tex} ( \mathrm { C } - 1 ) {/tex}.

Explanation



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Q 6. {tex}\mathrm{RNA}{/tex} is different from {tex}\mathrm{DNA}{/tex} because {tex}\mathrm{RNA}{/tex} contains

A

ribose sugar and thymine

ribose sugar and uracil

C

deoxyribose sugar and thymine

D

deoxyribose sugar and uracil.

Explanation

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Q 7. Complete hydrolysis of cellulose gives

A

D-fructose

B

D-ribose

D-glucose

D

L-glucose.

Explanation


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Q 8. Insulin production and its action in human body are responsible for the level of diabetes. This compound belongs to which of the following categories?

A

A co-enzyme

A hormone

C

An enzyme

D

An antibiotic.

Explanation


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Q 9. Identify the correct statement regarding enzymes.

A

Enzymes are specific biological catalysts that can normally function at very high temperatures {tex} ( T \sim 1000 \mathrm { K } ) {/tex}.

B

Enzymes are normally heterogeneous catalysts that are very specific in action.

C

Enzymes are specific biological catalysts that cannot be poisoned.

Enzymes are specific biological catalysts that possess well-defined active sites.

Explanation


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Q 10. The secondary structure of a protein refers to

A

fixed configuration of the polypeptide backbone

{tex}\alpha{/tex}-helical backbone

C

hydrophobic interactions

D

sequence of {tex} \alpha {/tex} -amino acids.

Explanation



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Q 11. Which base is present in {tex}\mathrm{RNA}{/tex} but not in {tex}\mathrm{DNA}{/tex}?

Uracil

B

Cytosine

C

Guanine

D

Thymine

Explanation


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Q 12. The functional group, which is found in amino acid is

A

{tex} - \mathrm { COOH } {/tex} group

B

{tex} - \mathrm { NH } _ { 2 } {/tex} group

C

{tex} - \mathrm { CH } _ { 3 } {/tex} group

both (a) and (b).

Explanation


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Q 13. {tex} \alpha -D - ( + ) - {/tex} glucose and {tex} \beta - D - ( + ) - {/tex} glucose are

A

enantiomers

B

conformers

C

epimers

anomers

Explanation



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Q 14. The reason for double helical structure of {tex}\mathrm{DNA}{/tex} is operation of

A

van der Waal's forces

B

dipole-dipole interaction

hydrogen bonding

D

electrostatic attractions.

Explanation


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Q 15. The change in optical rotation, with time, of freshly prepared solution of sugar is known as

A

Rotatory motion

B

Inversion

C

Specific rotation

Mutarotation

Explanation

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Q 16. Gun-cotton is

A

Nitrosucrose

Nitrocellulose

C

Nitroglucose

D

Nitropicrin

Explanation

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Q 17. Which of the following monosaccharide is a pentose

A

Galactose

B

Glucose

C

Fructose

Arabinose

Explanation

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Q 18. Amide group is present in

A

Lipids

B

Carbohydrates

C

Amino acids

Proteins

Explanation

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Q 19. Which of the following is a carbohydrate

A

Leucine

B

Albumin

lnulin

D

Maltase

Explanation

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Q 20. General formula for carbohydrates is

A

{tex} C _ { n } H _ { 2 n } O _ { 2 n + 2 } {/tex}

B

{tex} C _ { x } \left( H _ { 2 } O \right) _ { 2 x } {/tex}

{tex} C _ { x } \left( H _ { 2 } O \right) _ { y } {/tex}

D

None of these

Explanation

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Q 21. Benedict solution provides

A

{tex} A g ^ { + } {/tex}

B

{tex} L i ^ { + } {/tex}

{tex} C u ^ { + 2 } {/tex}

D

{tex} B a ^ { + 2 } {/tex}

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Q 22. Glucose gives silver mirror with Tollen's reagent. It shows the presence of

A

An acidic group

B

An alcoholic group

C

A ketonic group

An aldehydic group

Explanation

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Q 23. A certain compound gives negative test with ninhydrin and positive test with Benedict's solution. The compound is

A

A protein

A monosaccharide

C

A lipid

D

An amino acid

Explanation

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Q 24. An organic compound answers Molisch's test as well as Benedict'stest. But it does not answer Scliwanoff's test. Most probably, it is

A

Sucrose

B

Protein

C

Fructose

Maltose

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Q 25. Glucose when heated with {tex} C H _ { 3 } O H {/tex} in presence of dry {tex} H Cl {/tex} gas gives {tex} \alpha {/tex} and {tex} \beta - {/tex} methyl glucosides because it contains

A

An aldehyde group

B

{tex} \mathrm { A } - \mathrm { CH } _ { 2 } \mathrm { OH } {/tex} group

A ring structure

D

Five hydroxyl groups

Explanation