PYQSide ExamsMy practice

Biomolecules · Question 23

NEET 2016 (Phase 2)MCQMedium📈 Topic in 25% papers+4−1
1

The correct corresponding order of names of four aldoses with configuration given below [figure] respectively, is

  1. L-erythrose, L-threose, L-erythrose, D-threose
  2. D-threose, D-erythrose, L-threose, L-erythrose
  3. L-erythrose, L-threose, D-erythrose, D-threose
  4. D-erythrose, D-threose, L-erythrose, L-threose

Answer

(4) D-erythrose, D-threose, L-erythrose, L-threose

Solution

As per NCERT, a sugar is D if the –OH on the lowest asymmetric carbon (the one next to CH2OH) is on the right in the Fischer projection, and L if it is on the left.

Erythrose: the two –OH groups on the same side; threose: on opposite sides.

1st: –OH (C2) right, –OH (C3) right D-erythrose

2nd: –OH (C2) left, –OH (C3) right D-threose

3rd: –OH (C2) left, –OH (C3) left L-erythrose

4th: –OH (C2) right, –OH (C3) left L-threose

Answer: (4)

NEET 2016 (Phase 2)

Keep practising — Biomolecules

2

Which of the following hormones is produced under the condition of stress which stimulate glycogenolysis in the liver of human beings?

  1. Thyroxine
  2. Insulin
  3. Adrenaline
  4. Estradiol
AIPMT 2014
3

D(+)-glucose reacts with hydroxylamine and yields an oxime. The structure of the oxime would be

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
AIPMT 2014
4

In DNA, the linkages between different nitrogenous bases are

  1. phosphate linkage
  2. H-bonding
  3. glycosidic linkage
  4. peptide linkage
NEET 2013 (Karnataka)
5

Deficiency of vitamin B1 causes the disease

  1. convulsions
  2. beri-beri
  3. cheilosis
  4. sterility
AIPMT 2012 (Prelims)
6

Which one of the following sets of monosaccharides forms sucrose?

  1. -D-galactopyranose and -D-glucopyranose
  2. -D-glucopyranose and -D-fructofuranose
  3. -D-glucopyranose and -D-fructofuranose
  4. -D-glucopyranose and -D-fructopyranose
AIPMT 2012 (Prelims)
7

Which of the following is not a fat soluble vitamin?

  1. Vitamin B complex
  2. Vitamin D
  3. Vitamin E
  4. Vitamin A
AIPMT 2011 (Mains)
8

Which of the statements about "Denaturation" given below are correct?

  1. B and C
  2. A and C
  3. A and B
  4. A, B and C
AIPMT 2011 (Mains)
9

Which one of the following statements is not true regarding (+) lactose?

  1. On hydrolysis (+) lactose gives equal amount of D(+) glucose and D(+) galactose.
  2. (+) Lactose is a -glucoside formed by the union of a molecule of D(+) glucose and a molecule of D(+) galactose.
  3. (+) Lactose is a reducing sugar and does not exhibit mutarotation.
  4. (+) Lactose, C12H22O11 contains 8 –OH groups
AIPMT 2011 (Prelims)
10

Fructose reduces Tollens' reagent due to

  1. asymmetric carbons
  2. primary alcoholic group
  3. secondary alcoholic group
  4. enolisation of fructose followed by conversion to aldehyde by base
AIPMT 2010 (Mains)
11

Which one of the following does not exhibit the phenomenon of mutarotation?

  1. (+) Sucrose
  2. (+) Lactose
  3. (+) Maltose
  4. (−) Fructose
AIPMT 2010 (Prelims)

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