MolSynapse / Question bank / Biomolecules

Biomolecules

274 questions in 10 topics. 55 NEET level, 110 JEE Main, 109 JEE Advanced. Every question was written for this chapter and solved independently a second time before publication.

Practice this chapter Chapter guide

Carbohydrates: classification, glucose structure, reactions 46

Glucose, C6H12O6, is classified as
Oxidation of D-glucose with bromine water gives
Prolonged heating of glucose with HI gives n-hexane. This shows that glucose has
alpha-D-Glucopyranose and beta-D-glucopyranose differ in configuration at
Glucose reacts with acetic anhydride to give a pentaacetate. This indicates that glucose contains
The number of stereocentres in the open-chain form of D-fructose, HOCH2-CO-(CHOH)3-CH2OH, is
Glucose reduces Tollens reagent but does not give the Schiff test or form an addition product with NaHSO3. The...
A freshly prepared solution of pure alpha-D-glucopyranose has specific rotation +112 degrees, which falls on s...
All 46 questions on this topic

Disaccharides and polysaccharides, reducing sugars 27

On hydrolysis, sucrose gives
Which of the following does not reduce Fehling solution?
Cellulose is a polymer of
The storage polysaccharide of animals is
Lactose is a disaccharide made of
Complete hydrolysis of maltose gives
In sucrose, the glycosidic linkage joins
Sucrose does not reduce Fehling solution because
All 27 questions on this topic

Amino acids: zwitterions, isoelectric point 45

Which of the following natural alpha-amino acids is optically inactive?
Which of the following is an essential amino acid (as per the NCERT list)?
The zwitterionic (dipolar ion) form of glycine is represented by
Which of the following amino acids is basic in nature?
Alpha-amino acids react with ninhydrin on warming to give a coloured product. The colour is
Naturally occurring alpha-amino acids obtained from proteins belong to which stereochemical series?
Amino acids are crystalline solids with melting points much higher than those of haloalkanes or carboxylic aci...
In strongly acidic solution (pH about 1) alanine exists predominantly as
All 45 questions on this topic

Proteins: peptide bond, structure levels, denaturation 27

The linkage joining two amino acids in a protein is
The alpha-helix secondary structure of a protein is stabilised by
On denaturation of a protein, which structure remains intact?
Which of the following is a fibrous protein?
In the dipeptide Gly-Ala (written from N-terminal to C-terminal), the amino acid with the free -NH2 (or -NH3+)...
The number of peptide bonds in a linear octapeptide is
The peptide bond -CO-NH- has partial double-bond character and the six atoms around it lie in one plane. The c...
The number of different tripeptides that can be made by joining three different amino acids, each used exactly...
All 27 questions on this topic

Enzymes and vitamins 28

Most enzymes, which act as biological catalysts, are chemically
The enzyme that hydrolyses cane sugar (sucrose) into glucose and fructose is
Prolonged deficiency of vitamin C in the diet causes
Which one of the following vitamins is fat soluble?
The vitamin whose molecule contains the metal cobalt is
The enzyme urease catalyses the hydrolysis of
An enzyme E catalyses the reaction S <=> P at constant temperature. Which statement is correct?
An uncatalysed reaction has E_a = 75 kJ mol^-1 and the enzyme-catalysed reaction has E_a = 50 kJ mol^-1. Assum...
All 28 questions on this topic

Nucleic acids: nucleotides, DNA and RNA 46

A nucleotide is made up of
The sugar present in DNA is
Which base is present in RNA but not in DNA?
In the DNA double helix, adenine pairs with thymine through how many hydrogen bonds?
Which of the following is a purine base?
Which statement correctly distinguishes RNA from DNA?
The genetic code is read in groups of bases. There are 4 different bases and 20 amino acids to be coded. What ...
A DNA strand has the sequence 5^prime-ATGCCA-3^prime. The complementary strand, written from its 5^prime end t...
All 46 questions on this topic

Monosaccharide classification from drawn structures 14

The monosaccharide shown is classified as
The open-chain sugar shown is best classified as
Taking the carbonyl group as C-1 at the top, the sugar shown is best described as
The reference compound shown has the D configuration. Which of Structures A to D is a D-aldopentose?
The reference compound shown is the simplest ketose. Which of Structures A to D is a ketohexose?
The sugar shown is oxidised by bromine water. Which of Structures A to D is the major product?
The sugar shown is heated for a long time with excess HI and red phosphorus. Which of Structures A to D is the...
Consider the constitution of the open-chain sugar shown. Counting configurational stereoisomers only (all ster...
All 14 questions on this topic

Anomers, epimers and reducing sugars from drawings 14

The cyclic sugar shown is
Does the compound shown give a positive Tollens test?
The two open-chain sugars shown differ in configuration at only one stereocentre, C-2. They are
The two cyclic sugars shown (both D-pyranoses) differ in configuration at exactly one ring stereocentre other ...
The two open-chain sugars shown are both D-aldohexoses. Which description is correct?
The reference compound shown gives a positive Tollens test. Which of Structures A to D also gives a positive T...
The reference sugar shown undergoes mutarotation in water. Which of Structures A to D can also undergo mutarot...
The disaccharide shown has one glycosidic bond. Which description of it is correct?
All 14 questions on this topic

Amino acids from drawn structures: side chain, chirality, charge 14

The side chain of the amino acid shown is best classified as
How many stereocentres does the amino acid shown have?
The side chain of the amino acid shown is classified as
At its isoelectric point the amino acid shown exists mainly as a zwitterion. Which of Structures A to D repres...
The amino acid shown has which configuration, written as D/L and as R/S at its stereocentre?
The amino acid shown is classified, by side chain and dietary requirement, as
For the amino acid shown, pK_a1 (COOH) = 2.34 and pK_a2 (NH3+) = 9.69. Which of Structures A to D is the predo...
The amino acid shown has pK_a1 = 2.34 and pK_a2 = 9.60. What is its isoelectric point?
All 14 questions on this topic

Peptides and nucleotides from drawn structures 13

How many peptide bonds does the dipeptide shown contain?
Which residue is the N-terminal residue of the dipeptide shown?
The dipeptide shown is completely hydrolysed with aqueous acid (no racemisation). Which of Structures A to D s...
For the nucleoside shown, which row gives the name of the base and the number of hydrogen bonds it forms with ...
Which row correctly gives the sugar unit of the nucleoside shown and the nucleic acid in which it occurs?
In the nucleoside shown, which atom of the base forms the N-glycosidic bond to C-1' of the sugar?
Which of the following statements about the tripeptide shown is/are correct?
Which description of the nucleotide shown is correct?
All 13 questions on this topic