Solved Example: Biomolecules | Chemistry for JEE Main & Advanced PDF Download

 Page 1


JEE Solved Example on Biomolecules 
JEE Mains 
Q.1 The chromophore in the dye 
 
Ans: (D) Chromophore is the colouring agent, which is diazo group (-N = N-) 
 
Q2 At the isoelectric point for an amino acid the species present are 
 
Ans: (D) Zwitter ion is present 
 
Q3:  Secondary structure of a protein refers to 
(A) Mainly denatured proteins and structures of prosthetic groups 
(B) Regular folding patterns of contiguous portions of the polypeptide chain 
(C) Linear sequence of amino acid residues in the polypeptide chain 
(D) None of these 
Ans: (C) This is secondary structure of a protein 
 
 
 
Page 2


JEE Solved Example on Biomolecules 
JEE Mains 
Q.1 The chromophore in the dye 
 
Ans: (D) Chromophore is the colouring agent, which is diazo group (-N = N-) 
 
Q2 At the isoelectric point for an amino acid the species present are 
 
Ans: (D) Zwitter ion is present 
 
Q3:  Secondary structure of a protein refers to 
(A) Mainly denatured proteins and structures of prosthetic groups 
(B) Regular folding patterns of contiguous portions of the polypeptide chain 
(C) Linear sequence of amino acid residues in the polypeptide chain 
(D) None of these 
Ans: (C) This is secondary structure of a protein 
 
 
 
Q4 The general formula of carbohydrates is: 
(A) ?? ?? ?? ?? ?? +?? ?? 
(B) ?? ?? ?? ?? ?? ?? 
(C) ?? ?? (?? ?? ?? )
?? or ?? ?? (?? ?? ?? )
?? 
(D) ?? ?? (?? ?? ?? )
?? ?? 
Ans: (C) General formula of carbohydrates: 
C
n
(H
2
O)
?? or C
x
(H
2
O)
?? 
 
Q5:  Which of the following is a disaccharide? 
(A) Sucrose 
(B) Glucose 
(C) Fructose 
(D) Starch 
Ans: (A) Rest are all monosaccharide except sucrose. 
 
Q6:  The iron in hemoglobin is bound by 
(A) Hydrogen bonds 
(B) Chelation 
(C) Ionic bonds 
(D) Covalent bonds 
Ans: (B) Iron is bonded by co-ordination ring formation (chelation) 
 
Q7 Anomers have different 
(A) Properties 
(B) Melting points 
(C) Specific rotation 
(D) All of these 
Ans: (C) Anomers have different specific relation. 
 
 
 
 
 
Page 3


JEE Solved Example on Biomolecules 
JEE Mains 
Q.1 The chromophore in the dye 
 
Ans: (D) Chromophore is the colouring agent, which is diazo group (-N = N-) 
 
Q2 At the isoelectric point for an amino acid the species present are 
 
Ans: (D) Zwitter ion is present 
 
Q3:  Secondary structure of a protein refers to 
(A) Mainly denatured proteins and structures of prosthetic groups 
(B) Regular folding patterns of contiguous portions of the polypeptide chain 
(C) Linear sequence of amino acid residues in the polypeptide chain 
(D) None of these 
Ans: (C) This is secondary structure of a protein 
 
 
 
Q4 The general formula of carbohydrates is: 
(A) ?? ?? ?? ?? ?? +?? ?? 
(B) ?? ?? ?? ?? ?? ?? 
(C) ?? ?? (?? ?? ?? )
?? or ?? ?? (?? ?? ?? )
?? 
(D) ?? ?? (?? ?? ?? )
?? ?? 
Ans: (C) General formula of carbohydrates: 
C
n
(H
2
O)
?? or C
x
(H
2
O)
?? 
 
Q5:  Which of the following is a disaccharide? 
(A) Sucrose 
(B) Glucose 
(C) Fructose 
(D) Starch 
Ans: (A) Rest are all monosaccharide except sucrose. 
 
Q6:  The iron in hemoglobin is bound by 
(A) Hydrogen bonds 
(B) Chelation 
(C) Ionic bonds 
(D) Covalent bonds 
Ans: (B) Iron is bonded by co-ordination ring formation (chelation) 
 
Q7 Anomers have different 
(A) Properties 
(B) Melting points 
(C) Specific rotation 
(D) All of these 
Ans: (C) Anomers have different specific relation. 
 
 
 
 
 
Q8:  Peptide bond is 
(A) -???? - ???? - 
(B) ????
?? - ???? - ???? - ?? 
(C) ?? - ???? - ???? - ?? 
(D) -???????? ?? 
Ans: (A) Amide linkage (-CO - NH-) is called peptide bond 
 
Q9:  Glucose and Fructose are 
(A) Tautomers 
(B) Chain isomers 
(C) Functional isomers 
(D) Geometrical isomers 
Ans: (C) Glucose is a hydroxyl aldehyde whereas Fructose is a ketone. 
 
Q10:  Glucose is 
(A) Aldopentose 
(B) Aldohexose 
(C) Ketopentose 
(D) Ketohexose 
Ans: (B) Glucose is a hydroxy aldehyde with 6 carbon or aldehexose. 
 
Q11:  A substance which can act both as an antiseptic and disinfectant is 
(A) Aspirin 
(B) Chloroxylenol 
(C) Bithinal 
(D) Phenol 
Ans: (D) Phenol acts both as an antiseptic and disinfectant. 
Q12:  The reagent used in Ruff's degradation is 
(A) Baeyer's reagent 
(B) Tollen's reagent 
(C) Fentons' reagent 
(D) Benedict's reagent 
Ans: (C) Fenton's reagent (H
2
O
2
+ Fe) converts D -glucose (6 carbon) to D arabinose (5 carbon) 
 
 
 
Page 4


JEE Solved Example on Biomolecules 
JEE Mains 
Q.1 The chromophore in the dye 
 
Ans: (D) Chromophore is the colouring agent, which is diazo group (-N = N-) 
 
Q2 At the isoelectric point for an amino acid the species present are 
 
Ans: (D) Zwitter ion is present 
 
Q3:  Secondary structure of a protein refers to 
(A) Mainly denatured proteins and structures of prosthetic groups 
(B) Regular folding patterns of contiguous portions of the polypeptide chain 
(C) Linear sequence of amino acid residues in the polypeptide chain 
(D) None of these 
Ans: (C) This is secondary structure of a protein 
 
 
 
Q4 The general formula of carbohydrates is: 
(A) ?? ?? ?? ?? ?? +?? ?? 
(B) ?? ?? ?? ?? ?? ?? 
(C) ?? ?? (?? ?? ?? )
?? or ?? ?? (?? ?? ?? )
?? 
(D) ?? ?? (?? ?? ?? )
?? ?? 
Ans: (C) General formula of carbohydrates: 
C
n
(H
2
O)
?? or C
x
(H
2
O)
?? 
 
Q5:  Which of the following is a disaccharide? 
(A) Sucrose 
(B) Glucose 
(C) Fructose 
(D) Starch 
Ans: (A) Rest are all monosaccharide except sucrose. 
 
Q6:  The iron in hemoglobin is bound by 
(A) Hydrogen bonds 
(B) Chelation 
(C) Ionic bonds 
(D) Covalent bonds 
Ans: (B) Iron is bonded by co-ordination ring formation (chelation) 
 
Q7 Anomers have different 
(A) Properties 
(B) Melting points 
(C) Specific rotation 
(D) All of these 
Ans: (C) Anomers have different specific relation. 
 
 
 
 
 
Q8:  Peptide bond is 
(A) -???? - ???? - 
(B) ????
?? - ???? - ???? - ?? 
(C) ?? - ???? - ???? - ?? 
(D) -???????? ?? 
Ans: (A) Amide linkage (-CO - NH-) is called peptide bond 
 
Q9:  Glucose and Fructose are 
(A) Tautomers 
(B) Chain isomers 
(C) Functional isomers 
(D) Geometrical isomers 
Ans: (C) Glucose is a hydroxyl aldehyde whereas Fructose is a ketone. 
 
Q10:  Glucose is 
(A) Aldopentose 
(B) Aldohexose 
(C) Ketopentose 
(D) Ketohexose 
Ans: (B) Glucose is a hydroxy aldehyde with 6 carbon or aldehexose. 
 
Q11:  A substance which can act both as an antiseptic and disinfectant is 
(A) Aspirin 
(B) Chloroxylenol 
(C) Bithinal 
(D) Phenol 
Ans: (D) Phenol acts both as an antiseptic and disinfectant. 
Q12:  The reagent used in Ruff's degradation is 
(A) Baeyer's reagent 
(B) Tollen's reagent 
(C) Fentons' reagent 
(D) Benedict's reagent 
Ans: (C) Fenton's reagent (H
2
O
2
+ Fe) converts D -glucose (6 carbon) to D arabinose (5 carbon) 
 
 
 
Q13:  If ?? ????
 and ?? ????
 are the ionization constants of ?? ?? ?? +
?????????????? and ?? ?? ?? +
???????????? , 
respectively, the ???? of the solution at the isoelectric point is 
(A) ???? = ????
?? + ????
????
 
(B) ???? = (????
????
+ ????
????
)
?? /?? 
(C) ???? = (????
????
+ ????
????
)
?? /?? 
(D) ???? =
(????
????
+????
????
)
?? 
Ans: (D) At isoelectronic point. 
pH =
pk
a1
+ pk
a2
2
 
 
Q14:  Coordination polymerization was developed by 
(A) Zeigler and Natta 
(B) Linus Pauling 
(C) Beckamann 
(D) None of these 
Ans: (A) Zeigler and Natta developed zeigler Natta Catalysts (Al(C
2
H
5
)
3
+ TiCl
3
) which are used for 
coordination polymerization. 
 
Q15:  Teflon, polystyrene and neoprene are all 
(A) Copolymers 
(B) Condensation polymers 
(C) Homopolymers 
(D) Monomers 
Ans: (?? ) Teflon is homopolymer of tetraflourethylene. Polystyrene is a homopolymer of styrene. 
Neoprene is a homopolymer of chloroprene. 
 
 
Q16:  Carbohydrates which differ in configuration at the glycoside carbon (i.e. ?? ?? in aldose and ?? ?? 
in ketoses) are called 
(A) Anomers 
(B) Epimers 
(C) Diastereomers 
(D) Enantiomers 
Ans: (A) Anomer have different configurations at Glycosidic carbon and hence different specific 
rotation. 
 
 
Page 5


JEE Solved Example on Biomolecules 
JEE Mains 
Q.1 The chromophore in the dye 
 
Ans: (D) Chromophore is the colouring agent, which is diazo group (-N = N-) 
 
Q2 At the isoelectric point for an amino acid the species present are 
 
Ans: (D) Zwitter ion is present 
 
Q3:  Secondary structure of a protein refers to 
(A) Mainly denatured proteins and structures of prosthetic groups 
(B) Regular folding patterns of contiguous portions of the polypeptide chain 
(C) Linear sequence of amino acid residues in the polypeptide chain 
(D) None of these 
Ans: (C) This is secondary structure of a protein 
 
 
 
Q4 The general formula of carbohydrates is: 
(A) ?? ?? ?? ?? ?? +?? ?? 
(B) ?? ?? ?? ?? ?? ?? 
(C) ?? ?? (?? ?? ?? )
?? or ?? ?? (?? ?? ?? )
?? 
(D) ?? ?? (?? ?? ?? )
?? ?? 
Ans: (C) General formula of carbohydrates: 
C
n
(H
2
O)
?? or C
x
(H
2
O)
?? 
 
Q5:  Which of the following is a disaccharide? 
(A) Sucrose 
(B) Glucose 
(C) Fructose 
(D) Starch 
Ans: (A) Rest are all monosaccharide except sucrose. 
 
Q6:  The iron in hemoglobin is bound by 
(A) Hydrogen bonds 
(B) Chelation 
(C) Ionic bonds 
(D) Covalent bonds 
Ans: (B) Iron is bonded by co-ordination ring formation (chelation) 
 
Q7 Anomers have different 
(A) Properties 
(B) Melting points 
(C) Specific rotation 
(D) All of these 
Ans: (C) Anomers have different specific relation. 
 
 
 
 
 
Q8:  Peptide bond is 
(A) -???? - ???? - 
(B) ????
?? - ???? - ???? - ?? 
(C) ?? - ???? - ???? - ?? 
(D) -???????? ?? 
Ans: (A) Amide linkage (-CO - NH-) is called peptide bond 
 
Q9:  Glucose and Fructose are 
(A) Tautomers 
(B) Chain isomers 
(C) Functional isomers 
(D) Geometrical isomers 
Ans: (C) Glucose is a hydroxyl aldehyde whereas Fructose is a ketone. 
 
Q10:  Glucose is 
(A) Aldopentose 
(B) Aldohexose 
(C) Ketopentose 
(D) Ketohexose 
Ans: (B) Glucose is a hydroxy aldehyde with 6 carbon or aldehexose. 
 
Q11:  A substance which can act both as an antiseptic and disinfectant is 
(A) Aspirin 
(B) Chloroxylenol 
(C) Bithinal 
(D) Phenol 
Ans: (D) Phenol acts both as an antiseptic and disinfectant. 
Q12:  The reagent used in Ruff's degradation is 
(A) Baeyer's reagent 
(B) Tollen's reagent 
(C) Fentons' reagent 
(D) Benedict's reagent 
Ans: (C) Fenton's reagent (H
2
O
2
+ Fe) converts D -glucose (6 carbon) to D arabinose (5 carbon) 
 
 
 
Q13:  If ?? ????
 and ?? ????
 are the ionization constants of ?? ?? ?? +
?????????????? and ?? ?? ?? +
???????????? , 
respectively, the ???? of the solution at the isoelectric point is 
(A) ???? = ????
?? + ????
????
 
(B) ???? = (????
????
+ ????
????
)
?? /?? 
(C) ???? = (????
????
+ ????
????
)
?? /?? 
(D) ???? =
(????
????
+????
????
)
?? 
Ans: (D) At isoelectronic point. 
pH =
pk
a1
+ pk
a2
2
 
 
Q14:  Coordination polymerization was developed by 
(A) Zeigler and Natta 
(B) Linus Pauling 
(C) Beckamann 
(D) None of these 
Ans: (A) Zeigler and Natta developed zeigler Natta Catalysts (Al(C
2
H
5
)
3
+ TiCl
3
) which are used for 
coordination polymerization. 
 
Q15:  Teflon, polystyrene and neoprene are all 
(A) Copolymers 
(B) Condensation polymers 
(C) Homopolymers 
(D) Monomers 
Ans: (?? ) Teflon is homopolymer of tetraflourethylene. Polystyrene is a homopolymer of styrene. 
Neoprene is a homopolymer of chloroprene. 
 
 
Q16:  Carbohydrates which differ in configuration at the glycoside carbon (i.e. ?? ?? in aldose and ?? ?? 
in ketoses) are called 
(A) Anomers 
(B) Epimers 
(C) Diastereomers 
(D) Enantiomers 
Ans: (A) Anomer have different configurations at Glycosidic carbon and hence different specific 
rotation. 
 
 
 
 
Q17:  Choose the correct relationship for ?? -D-glucose 
(1) and ?? -D-glucose (2) 
(A) ?? and ?? are epimers 
(B) ?? and ?? are crystal modification 
(C) ?? is a pyranose sugar and ?? is furanose sugar 
(D) ?? is an aldose and ?? is a ketose. 
Ans: (A) They are called epimers. 
 
 
Q18:  Natural rubber is a polymer of 
(A) Chloroprene 
(B) Isoprene 
(C) 1,3-Butadiene 
(d) None 
Ans: (B) Natural rubber is polymer of isoprene 
 
 
Q19:  Hydrolysis of sucrose is called 
(A) Saponification 
(B) Inversion 
(C) Esterification 
(D) Hydration 
Ans: (B) It is called inversion as sucrose, which is dextrorotatory gives a laevorotatory mixture on 
dilution.