PYQSide ExamsMy practice

Biomolecules · Question 48

AIPMT 2004MCQMedium📈 Topic in 25% papers+4−1
1

Number of chiral carbons in -D-(+)-glucose is

  1. five
  2. six
  3. three
  4. four

Answer

(1) five

Solution

A chiral carbon is an sp3 carbon atom attached to four different groups.

As per NCERT, -D-(+)-glucose is the cyclic (pyranose) form of glucose, formed when the C-5 –OH adds to the C-1 aldehyde group, giving a six-membered ring with a new –OH at C-1.

C-1 (anomeric carbon) now carries H, OH, ring O and C-2, so it becomes chiral.

C-2, C-3, C-4 and C-5 each remain attached to four different groups, so each is chiral.

C-6 (-CH2OH) is not chiral.

Number of chiral carbons = 5

Answer: (1)

AIPMT 2004

Keep practising — Biomolecules

2

The helical structure of protein is stabilised by

  1. dipeptide bonds
  2. hydrogen bonds
  3. ether bonds
  4. peptide bonds
AIPMT 2004
3

Which of the following structures represents the peptide chain?

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
AIPMT 2004
4

The enzyme which hydrolyses triglycerides to fatty acids and glycerol is called

  1. maltase
  2. lipase
  3. zymase
  4. pepsin
Out of syllabusAIPMT 2004
5

Glycolysis is

  1. oxidation of glucose to glutamate
  2. conversion of pyruvate to citrate
  3. oxidation of glucose to pyruvate
  4. conversion of glucose to haem
AIPMT 2003
6

Phospholipids are esters of glycerol with

  1. three carboxylic acid residues
  2. two carboxylic acid residues and one phosphate group
  3. one carboxylic acid residue and two phosphate groups
  4. three phosphate groups
AIPMT 2003
7

Chargaff's rule states that in an organism

  1. amount of adenine (A) is equal to that of thymine (T) and the amount of guanine (G) is equal to that of cytosine (C)
  2. amount of adenine (A) is equal to that of guanine (G) and the amount of thymine (T) is equal to that of cytosine (C)
  3. amount of adenine (A) is equal to that of cytosine (C) and the amount of thymine (T) is equal to that of guanine (G)
  4. amounts of all bases are equal
AIPMT 2003
8

Enzymes are made up of

  1. edible proteins
  2. proteins with specific structure
  3. nitrogen containing carbohydrates
  4. carbohydrates
AIPMT 2002
9

Which is not a true statement?

  1. -carbon of -amino acid is asymmetric
  2. All proteins are found in L-form
  3. Human body can synthesise all proteins it needs
  4. At pH = 7, both amino and carboxylic groups exist in ionised form
AIPMT 2002
10

Cellulose is polymer of

  1. glucose
  2. fructose
  3. ribose
  4. sucrose
Out of syllabusAIPMT 2002
11

Which of the following give positive Fehling solution test?

  1. Sucrose
  2. Glucose
  3. Fats
  4. Protein
AIPMT 2001

All Biomolecules PYQs →

PDFDownload Biomolecules PYQs as PDF Free, with answer key and a QR code to every solution — print it or study offline⬇
All NEET Chemistry chapters
Physical ChemistrySome Basic Concepts of ChemistryStructure of AtomStates of MatterThermodynamicsEquilibriumRedox ReactionsSolid StateSolutionsElectrochemistryChemical KineticsSurface Chemistry
Inorganic ChemistryClassification of Elements and Periodicity in PropertiesChemical Bonding and Molecular StructureHydrogens-Block Elementsp-Block Elements (Group 13 & 14)Environmental ChemistryGeneral Principles of Isolation of Elementsp-Block Elements (Group 15–18)d- and f-Block ElementsCoordination Compounds
Organic ChemistryOrganic Chemistry – Some Basic Principles and TechniquesIsomerismHydrocarbonsHaloalkanes and HaloarenesAlcohols, Phenols and EthersAldehydes, Ketones and Carboxylic AcidsAminesBiomoleculesPolymersChemistry in Everyday LifePrinciples Related to Practical Chemistry