JEE Chemistry Biomolecules MCQs Set A

Question: Which one of the following compounds is different from the rest?

• a) Glucose
• b) Maltose
• c) Sucrose
• d) Lactose

Answer: Glucose

Question: The two functional groups present in a typical carbohydrate are

• a) – OH and – CHO
• b) – CHO and – COOH
• c) > C = O and – OH
• d) – OH and – COOH

Answer: – OH and – CHO

Question: When glucose reacts with bromine water, the main product is

• a) gluconic acid
• b) saccharic acid
• c) glyceraldehyde
• d) acetic acid

Answer: gluconic acid

Question: Glucose does not react with

• a) NaHSO₃
• b) H₂NOH
• c) HI
• d) None of these

Answer: NaHSO₃

Question: Glucose reacts with acetic anhydride to form

• a) penta-acetate
• b) monoacetate
• c) tetra-acetate
• d) hexa-acetate

Answer: penta-acetate

Question: Reduction of glucose by HI suggest that

• a) six carbon atoms are arranged in straight chain
• b) cyclic structure of glucose
• c) presence of –CHO group
• d) presence of OH groups

Answer: six carbon atoms are arranged in straight chain

Question: The reaction of glucose with red P + HI is called

• a) Reduction
• b) Reformatsky reaction
• c) Sandmeyer’s reaction
• d) Gattermann’s reaction

Answer: Reduction

Question: Which of the following reactions of glucose can be explained only by its cyclic structure?

• a) Pentaacetate of glucose does not react with hydroxylamine
• b) Glucose is oxidised by nitric acid to gluconic acid
• c) Glucose reacts with hydroxylamine to form an oxime
• d) Glucose forms pentaacetate

Answer: Pentaacetate of glucose does not react with hydroxylamine

Question: Which is the least stable form of glucose ?

• a) Open chain structure
• b) All are equally stable
• c) 
• d)

  

Answer: Open chain structure

Question: Isomerization of glucose produces

• a) fructose
• b) allose
• c) galactose
• d) mannose

Answer: fructose

Question: A solution of D-glucose in water rotates the plane polarised light

• a) to the right
• b) to either side
• c) to the left
• d) None of these

Answer: to the right

Question:

• a) 5
• b) 3
• c) 4
• d) 6

Answer: 5

Question:

• a) configuration
• b) size of hemiacetal ring
• c) conformation
• d) number of OH groups

Answer: configuration

Question:

• a) anomers
• b) enantiomers
• c) isomers
• d) epimers

Answer: anomers

Question: Which of the following carbohydrates are branched polymer of glucose?

(i) Amylose   (ii) Amylopectin
(iii) Cellulose (iv) Glycogen

• a) (ii) and (iv)
• b) (i), (ii) and (iii)
• c) (i) and (ii)
• d) (iii) and (iv)

Answer: (ii) and (iv)

Question:

• a) 5
• b) 4
• c) 3
• d) 6

Answer: 5

Question: Which of the following reagent cannot distinguish between glucose and fructose?

• a) Tollen’s reagent
• b) All of these
• c) Fehling’s solution
• d) Benedict’s solution

Answer: Tollen’s reagent

Question: Maltose and glucose are

• a) reducing sugar
• b) oxidising sugar
• c) first is oxidising and second is reducing sugar
• d) both are non-reducing sugar

Answer: reducing sugar

Question: Choose the correct relationship for glucose and fructose

• a) these are functional isomers
• b) these are chain isomers
• c) these are position isomers
• d) All of these

Answer: these are functional isomers

Question: The pair of compounds in which both the compounds give positive test with Tollen’s reagent is

• a) Glucose and Fructose
• b) Acetophenone and Hexanal
• c) Fructose and Sucrose
• d) Glucose and Sucrose

Answer: Glucose and Fructose

Question: Biomolecules are

• a) carbohydrates, proteins and fats
• b) alcohols and phenols
• c) acids and esters
• d) aldehydes and ketones

Answer: carbohydrates, proteins and fats

Question: Which of the following is a disaccharide ?

• a) Lactose
• b) Cellulose
• c) Starch
• d) Fructose

Answer: Lactose

Question:  The sugar that is characteristic of milk is

• a) lactose
• b) maltose
• c) ribose
• d) galactose

Answer: lactose

Question: Which one is a disaccharide ?

• a) Sucrose
• b) Fructose
• c) Glucose
• d) Xylose

Answer: Sucrose

Question: Which of the following monosaccharide is pentose ?

• a) Arabinose
• b) Glucose
• c) Fructose
• d) Galactose

Answer: Arabinose

Question: The commonest disaccharide has the molecular formula

• a) C₁₂H₂₂O₁₁
• b) C₁₀H₂₀O₁₀
• c) C₁₀H₁₈O₉
• d) None of these

Answer: C₁₂H₂₂O₁₁

Question: Monosaccharides usually contains ... carbon atoms.

• a) C₃ to C₁₀
• b) C₄ to C₁₀
• c) C₁ to C₆
• d) None of these

Answer: C₃ to C₁₀

Question: Which one of the following compounds is found abudnantly in nature?

• a) Cellulose
• b) Starch
• c) Fructose
• d) Glucose

Answer: Cellulose

Question: A carbohydrate that cannot be hydrolysed into simpler units is called

• a) monosaccharides
• b) trisaccharides
• c) polysaccharides
• d) disachharides

Answer: monosaccharides

Question: Which of the following statements is incorrect ?

• a) Cellulose and sucrose are polysaccharide.
• b) Maltose gives two molecules of glucose only
• c) Polysaccharides are not sweet in taste
• d) Polysaccharides are also known as non-sugars

Answer: Cellulose and sucrose are polysaccharide.

Question: Reducing sugars reduce

• a) both
• b) only Fehling’s solution
• c) only Tollen’s solution
• d) None of these

Answer: both

Question: Which among the following is the simplest sugar?

• a) Glucose
• b) Cellulose
• c) Starch
• d) None of these

Answer: Glucose

Question: Glucose can’t be classified as

• a) oligosaccharide
• b) carbohydrate
• c) hexose
• d) aldose

Answer: oligosaccharide

Question:

• a) (i) and (iii)
• b) (i) and (ii)
• c) (ii) only
• d) (ii) and (iii)

Answer: (i) and (iii)

Question: Which of the following gives positive Fehling solution test?

• a) Glucose
• b) Protein
• c) Sucrose
• d) Fats

Answer: Glucose

Question: Which of the following statements is incorrect regarding glucose?

• a) It is the least abundant organic compound on earth.
• b) It is monomer of cellulose
• c) It is also known as dextrose
• d) It is an aldohexose

Answer: It is the least abundant organic compound on earth.

Question: Glucose gives silver mirror test with Tollen’s reagent. It shows the presence of

• a) aldehyde group
• b) alcoholic group
• c) acidic group
• d) ketonic group

Answer: aldehyde group

Question: The symbols D and L represents

• a) the relative configuration of a particular stereoisomer.
• b) the dextrorotatory nature of molecule
• c) the levorotatory nature of molecule
• d) the optical activity of compounds.

Answer: the relative configuration of a particular stereoisomer.

Question:

• a) (i) and (iii)
• b) (ii) and (iii)
• c) (ii) and (iv)
• d) (i) only

Answer: (i) and (iii)

Question: The function of glucose is to

• a) provides energy
• b) prevent diseases
• c) promote growth
• d) perform all above

Answer: provides energy

Question: The letter D and L in carbohydrates represent

• a) its configuration
• b) its mutarotation
• c) its optical rotation
• d) its direct synthesis

Answer: its configuration

Question: Which of the following statement is correct about fructose?

• a) It exists in the two cyclic forms which is obtained by the addition of OH at C-5 to the >C=O group
• b) It exists as six membered ring
• c) It is named as furanose as it contain one oxygen and six carbon atom
• d) It is dextrorotatory compound

Answer: It exists in the two cyclic forms which is obtained by the addition of OH at C-5 to the >C=O group

Question: Fructose is

• a) a hemiketal
• b) a hemiacetal
• c) an acetal
• d) a ketal

Answer: a hemiketal

Question: The sugar present in fruits is

• a) fructose
• b) sucrose
• c) glucose
• d) galactose

Answer: fructose

Question: Three cyclic structures of monosaccharides are given below  which of these are anomers

• a) I and II
• b) I and III
• c) II and III
• d) III is anomer of I and II

Answer: I and II

Question: The sugar present in honey is

• a) fructose
• b) sucrose
• c) glucose
• d) maltose

Answer: fructose

Question: Which of the following is the sweetest sugar?

• a) Fructose
• b) Sucrose
• c) Glucose
• d) Maltose

Answer: Fructose

Question: Cellulose is a polymer of

• a) Glucose
• b) Ribose
• c) Sucrose
• d) Fructose

Answer: Glucose

Question: Sucrose on hydrolysis gives

• a) glucose + fructose
• b) fructose + fructose
• c) fructose+ribose
• d) glucose+glucose

Answer: glucose + fructose

Question: The presence or absence of hydroxyl group on which carbon atom of sugar differentiates RNA and DNA?

• a) 2nd
• b) 4th
• c) 1st
• d) 3rd

Answer: 2nd

Question: Carbohydrates are stored in the body as

• a) glycogen
• b) starch
• c) sugars
• d) glucose

Answer: glycogen

Question: A carbohydrate insoluble in water is

• a) cellulose
• b) glucose
• c) fructose
• d) sucrose

Answer: cellulose

Question: Which of the following carbohydrate does not correspond to the general formula C_x(H₂O)_y ?

• a) 2-Deoxyribose
• b) Arabinose
• c) Glucose
• d) Fructose

Answer: 2-Deoxyribose

Question: Lactose is made of

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: Which of the following monosaccharides are present as five membered cyclic structure (furanose structure)?

(i) Ribose      (ii) Glucose
(iii) Fructose (iv) Galactose

• a) (i) and (iii)
• b) (ii) and (iii)
• c) (i) and (ii)
• d) (iii) and (iv)

Answer: (i) and (iii)

Question: Invert sugar is

• a) equimolecular mixture of glucose and fructose
• b) chemically inactive form of sugar
• c) mixture of glucose and sucrose
• d) a variety of cane sugar

Answer: equimolecular mixture of glucose and fructose

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

• a) (+) – Sucrose
• b) (+) – Maltose
• c) (+) – Lactose
• d) (–) – Fructose

Answer: (+) – Sucrose

Question:

• a) Amylopectin
• b) Glucose
• c) Cellulose
• d) Amylose

Answer: Amylopectin

Question:

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: Sucrose which is dextrorotatory in nature after hydrolysis gives glucose and fructose, among which

(i) Glucose is laevorotatory and fructose is dextrorotatory.
(ii) Glucose is dextrorotatory and fructose is laevorotatory
(iii) The mixture is laevorotatory.
(iv) Both are dextrorotatory.

• a) (ii) and (iii)
• b) (iii) only
• c) (i) and (iii)
• d) (iii) and (iv)

Question:

• a) long unbranched chain, C1– C4.
• b) branched chain, C1– C6
• c) branched chain, C1 – C4.
• d) long unbranched chain, C1– C6.

Answer: long unbranched chain, C1– C4.

Question:

• a) branched chain, C1– C4, C1– C6
• b) unbranched chain, C1– C4, C1– C6
• c) unbranched chain, C1– C6, C1– C4
• d) branched chain, C1– C6, C1– C4.

Answer: branched chain, C1– C4, C1– C6

Question: Which of the following is incorrect about cellulose?

• a)

  

• b) It is a branched chain disaccharide
• c) It is a major constituent of cell wall of plant cells
• d) The glycosidic linkage between two units is found between C1 of one unit and C4 of next unit.

Answer:

Question: Which of the following is also known as animal starch?

• a) Glycogen
• b) Cellulose
• c) Glycine
• d) Amylose

Answer: Glycogen

Question: Select the uses of carbohydrates

• a) All of the above
• b) They are used in furniture, cotton fibre, lacquers
• c) These are used as storage molecules
• d) Honey is used as instant source of energy by vaids in ayurvedic system of medicine

Answer: All of the above

Question: The number of essential amino acids in man is

• a) 10
• b) 20
• c) 8
• d) 18

Answer: 10

Question: Amino acids are the building blocks of

• a) proteins
• b) carbohydrates
• c) fats
• d) vitamins

Answer: proteins

Question: Which one of the amino acids can be synthesised in the body?

• a) Alanine
• b) Valine
• c) Lysine
• d) Histidine

Answer: Alanine

Question:

• a) lysin
• b) glycine
• c) serine
• d) proline

Answer: lysin

Question: Two functional group that are present in all amino acids are the

• a) carboxyl, amino
• b) hydroxy, amine
• c) hydroxy, amide
• d) carboxyl, amide

Answer: carboxyl, amino

Question: Which of the following is not an optically active amino acid?

• a) Glycine
• b) Valine
• c) Leucine
• d) Arginine

Answer: Glycine

Question: In aqueous solution, an amino acid exists as

• a) zwitter ion
• b) anion
• c) cation
• d) dianion

Answer: zwitter ion

Question: Which one of the following statements is correct?

• a) All amino acids except glycine are optically active
• b) All amino acids except glutamic acids are optically active
• c) All amino acids are optically active
• d) All amino acids except lysine are optically active

Answer: All amino acids except glycine are optically active

Question: Amino acids generally exist in the form of Zwitter ions. This means they contain

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: Which of the following molecules is capable of forming Zwitter ion?

• a) NH₂CH₂COOH
• b) CH₃CH₂NH₂
• c) CH₃CH₂COOH
• d) All of these

Answer: NH₂CH₂COOH

Question:

• a) Proline is a secondary amine
• b) Proline is a dicarboxylic acid
• c) Proline contains aromatic group
• d) Proline is optically inactive

Answer: Proline is a secondary amine

Question:  The linkage present in proteins and peptides is

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: Which one of the following structures represents the peptide chain?

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: Simplest proteins has one peptide linkage. It is

• a) dipeptide
• b) oligopeptide
• c) tripeptide
• d) tetrapeptide

Answer: dipeptide

Question: A nanopeptide contain how many peptide bond

• a) 8
• b) 7
• c) 9
• d) 10

Answer: 8