Biomolecule – JEE Main Previous Year Questions with Solutions

JEE Main Previous Year Papers Questions of Chemistry with Solutions are available at eSaral. Practicing JEE Mains chapter wise questions of Chemistry will help the JEE aspirants in realizing the question pattern as well as help in analyzing weak & strong areas.



Previous Years AIEEE/JEE Main Questions

Q. The two functional groups present in a typical carbohydrate are :-

(1) >C = O and –OH (2) –OH and –CHO (3) –OH and –COOH (4) –CHO and –COOH


Sol. (2)

Q. Biurest test is not given by :-

(1) proteins (2) carbohydrates (3) polypeptides (4) urea


Sol. (2)

Q. The presence or absence of hydroxy group on which carbon atom of sugar differentiates RNA and DNA?

(1) 3rd (2) 4th (3) 1st (4) 2nd


Sol. (4)

Q. The change in the optical rotation of freshly prepared solution of glucose is known as :-

(1) tautomerism (2) racemisation (3) specific rotation (4) mutarotation


Sol. (4)

Q. Which one of the following statements is correct ?

(1) All amino acids except glutamic acid are optically active

(2) All amino acids except lysine are optically active

(3) All amino acids are optically active

(4) All amino acids except glycine are optically active


Sol. (4)

Q. Synthesis of each molecule of glucose in photosynthesis involves :-

(1) 18 molecules of ATP

(2) 10 molecules of ATP

(3) 8 molecules of ATP

(4) 6 molecules of ATP

JEE Main -2013

Sol. (1)

Six rounds of the Calvin cycle are required, because one carbon atom is reduced in each round. Twelve molecules of ATP are expended. An additional six molecular of ATP are spent in regenerating ribulose-1, 5-biphosphate

$6 \mathrm{CO}_{2}+18 \mathrm{ATP}+12 \mathrm{NADPH}+12 \mathrm{H}_{2} \mathrm{O} \rightarrow$

$\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}+18 \mathrm{ADP}+18 \mathrm{P}_{\mathrm{i}}+12 \mathrm{NADP}+6 \mathrm{H} \oplus$

Reference : NCERT 11th class chapter-13 (Photosynthesis Pg. 217, 218 in higher plants.

Calvin cycle where sugar is synthesised is as follows :

The Calvin cycle proceeds in three stages (1) carboxylation, during which $\mathrm{CO}_{2}$ combines with ribulose-1.5-bisphosphate (2) reduction, during which carbohydrate is formed at the expense of the photochemically made ATP and NADPH and (3) regeneration during which the $\mathrm{CO}_{2}$ acceptor ribulose-1,5-bisphosphate is formed again so that the cylcle continues.

It might help you to understand all of this if we look at what goes in and what comes out of the Calvin cycle.

Q. Which one of the following bases is not present in DNA ?

(1) Cytosine (2) Thymine (3) Quinoline (4) Adenine

JEE-Main 2014

Sol. (3)

All cytosine, thymine and adenine are present in DNA. Only quinoline is not present in DNA.

Q. Which of the vitamins given below is water soluble?

(1) Vitamin E

(2) Vitamin K

(3) Vitamin C

(4) Vitamin D

JEE-Main 2015

Sol. (3)

Vitamine C is soluble in water due to H-Bonding & all other vitamines given in question are fat soluble.

Q. Complete hydrolysis of starch gives :

(1) glucose and fructose in equimolar amounts

(2) glucose only

(3) galactose and fructose in equimolar amounts

(4) glucose and galactose in equimolar amounts

JEE-Main(Online) – 2015

Sol. (2)

Starch is polymer of Glucose

Q. Accumulation of which of the following molecules in the muscles occurs as a result of vigorous exercise :-

(1) Pyruvic acid

(2) L-lactic acid

(3) Glycogen

(4) Glucose

JEE-Main(Online) – 2015

Sol. (2)

Q. Consider the following sequence for aspartic acid:

The pI (isoelectric point) of aspartic acid is :

(1) 1.88 (2) 2.77 (3) 3.65 (4) 5.74

JEE-Main(Online) – 2016

Sol. (4)

Q. Observation of “Rhumann’s purple” is a confirmatory test for the presence of :

(1) Starch

(2) Reducing sugar

(3) Cupric ion

(4) Protein

JEE-Main(Online) – 2017

Sol. (1)

Q. Which of the following compounds will behave as a reducing sugar in an aqueous KOH solution ?

JEE-Main 2017

Sol. (1)

(1) Ester in presence of Aqueous KOH solution give SNAE reaction so following reaction takes place


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