HOTs Biomolecules Class 12 Chemistry

Please refer to Biomolecules HOTs Class 12 Chemistry provided below with Biomolecules. All HOTs for Class 12 Chemistry with answers provided below have been designed as per the latest syllabus and examination petter issued by CBSE, NCERT, KVS. Students of Standard 12 Chemistry should learn the solved HOTS for Class 12 Chemistry provided below to gain better marks in examinations.

Biomolecules Class 12 Chemistry HOTs

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

Question. The sugar that is characteristic of milk is
(a) maltose
(b) ribose
(c) lactose
(d) galactose

Question. Glucose reacts with acetic anhydride to form
(a) monoacetate
(b) tetra-acetate
(c) penta-acetate
(d) hexa-acetate

Question. Which of the following monosaccharide is pentose ?
(a) Glucose
(b) Fructose
(c) Arabinose
(d) Galactose

Question. The number of chiral carbon atoms present in cyclic structure α-D(+) glucose
(a) 3
(b) 4
(c) 6
(d) 5

Question. Glycogen is a branched chain polymer of α-D-glucose units in which chain is formed by C1–C4 glycosidic linkage whereas branching occurs by the formation of C1-C6 glycosidic linkage. Structure of glycogen is similar to______.
(a) Amylose
(b) Amylopectin
(c) Cellulose
(d) Glucose

Question.Fructose is
(a) a hemiacetal
(b) an acetal
(c) a hemiketal
(d) a ketal

Question. Which of the following carbohydrate does not correspond to the general formula Cx(H₂O)y ?
(a) Glucose
(b) 2-Deoxyribose
(c) Fructose
(d) Arabinose

Question. Which of the following statements is incorrect ?
(a) Maltose gives two molecules of glucose only.
(b) Cellulose and sucrose are polysaccharide.
(c) Polysaccharides are not sweet in taste.
(d) Polysaccharides are also known as non-sugars.

Question. The two forms of D—glucopyranose obtained from the solution of D—glucose are called
(a) isomers
(b) anomers
(c) epimers
(d) enantiomers

Question. Which among the following is the simplest sugar?
(a) Glucose
(b) Starch
(c) Cellulose
(d) None of these

Question. Sucrose on hydrolysis gives
(a) fructose+ribose
(b) glucose + fructose
(c) glucose+glucose
(d) fructose + fructose

Question. Glucose can’t be classified as
(a) hexose
(b) carbohydrate
(c) aldose
(d) oligosaccharide

Question. Carbohydrates are stored in the body as
(a) sugars
(b) starch
(c) glucose
(d) glycogen

Question. Which of the following gives positive Fehling solution test?
(a) Protein
(b) Sucrose
(c) Glucose
(d) Fats

Question. Which of the following correctly represents the cyclic structure of β–D–(–)– fructo furanose.

Question. Glucose gives silver mirror test with Tollen’s reagent. It shows the presence of
(a) acidic group
(b) alcoholic group
(c) ketonic group
(d) aldehyde group

Question. A solution of D-glucose in water rotates the plane polarised light
(a) to the right
(b) to the left
(c) to either side
(d) None of these

Question. Which one of the following compounds is found abudnantly in nature?
(a) Fructose
(b) Starch
(c) Glucose
(d) Cellulose

Question. The symbols D and L represents
(a) the optical activity of compounds.
(b) the relative configuration of a particular stereoisomer.
(c) the dextrorotatory nature of molecule.
(d) the levorotatory nature of molecule

Question. The commonest disaccharide has the molecular formula
(a) C₁₀H₁₈O₉
(b) C₁₀H₂₀O₁₀
(c) C₁₈H₂₂O₁₁
(d) C₁₂H₂₂O₁₁

Question. Which one of the following compounds is different from the rest?
(a) Sucrose
(b) Maltose
(c) Lactose
(d) Glucose

Question. Monosaccharides usually contains … carbon atoms.
(a) C₃ to C₁₀
(b) C₁ to C₆
(c) C₄ to C₁₀
(d) C₅ to C₈

Question. When glucose reacts with bromine water, the main product is
(a) gluconic acid
(b) glyceraldehyde
(c) saccharic acid
(d) acetic acid

Question. Glucose does not react with
(a) Br₂/H₂O
(b) H₂NOH
(c) HI
(d) NaHSO₃

Question. Which of the following statements is incorrect regarding glucose?
(a) It is an aldohexose.
(b) It is also known as dextrose
(c) It is monomer of cellulose.
(d) It is the least abundant organic compound on earth.

Question. Cellulose is a polymer of
(a) Glucose
(b) Fructose
(c) Ribose
(d) Sucrose

Question. A carbohydrate that cannot be hydrolysed into simpler units is called
(a) polysaccharides
(b) trisaccharides
(c) disachharides
(d) monosaccharides

Question. Which of the following reactions of glucose can be explained only by its cyclic structure?
(a) Glucose forms pentaacetate
(b) Glucose reacts with hydroxylamine to form an oxime
(c) Pentaacetate of glucose does not react with hydroxylamine
(d) Glucose is oxidised by nitric acid to gluconic acid

Question. Which one is a disaccharide ?
(a) Glucose
(b) Fructose
(c) Xylose
(d) Sucrose

CRITICAL THINKING TYPE QUESTIONS

Question. Which functional group participates in disulphide bond formation in proteins?
(a) Thioester
(b) Thioether
(c) Thiol
(d) Thiolactone

Question. Select the false statement about the cyclic glucose.
(a) If the OH group is added to CHO group it will form cyclic hemiacetal structure
(b) Glucose form six-membered ring in which –OH is at C–5 position
(c) Melting point of α-glucose is 423 K and of β-glucose is 419 K

Question. Glycosidic linkage is actually an
(a) Carbonyl bond
(b) Ether bond
(c) Ester bond
(d) Amide bond

Question. In disaccharides, if the reducing groups of monosaccharides i.e., aldehydic or ketonic groups are bonded, these are nonreducing sugars. Which of the following disaccharide is a non-reducing sugar?

Question.

Which statement is incorrect about peptide bond?
(a) C — N bond length in proteins is longer than usual bond length of the C — N bond
(b) Spectroscopic analysis shows planar structure of the

(c) C — N bond length in proteins is smaller than usual bond length of the C—N bond
(d) None of the above

Question. Glucose molecule reacts with ‘X’ number of molecules of phenylhydrazine to yield osazone. The value of ‘X’ is
(a) four
(b) one
(c) two
(d) three

Question. Optical rotation of some compound along with their structures are given below which of them have D configuration.

(a) I, II, III
(b) II, III
(c) I, II
(d) III

Question. When α-D-glucose and β-D-glucose are dissolved in water in two separate beakers I and II respectively and allowed to stand, then –
(a) specific rotation in beaker I will decrease while in II will increase upto a constant value
(b) the specific rotation of equilibrium mixture in two beakers will be different
(c) the equilibrium mixture in both beakers will be leavorotatory
(d) the equilibrium mixture in both beakers will contain only cyclic form of glucose

Question. Vitamin C must be supplied regularly in diet because
(a) it is water soluble hence excreted in urine and can’t be stored in the body
(b) it is fat soluble hence stored in the body and cannot be used on regular basis
(c) it is required in a large amount by the body hence supplied regularly
(d) it is water soluble hence used by the body on daily basis and is to be supplied regularly. 

Question. Structure of a disaccharide formed by glucose and fructose is given below. Identify anomeric carbon atoms in monosaccharide units.

(a) ‘a’ carbon of glucose and ‘a’ carbon of fructose.
(b) ‘a’ carbon of glucose and ‘e’ carbon of fructose.
(c) ‘a’ carbon of glucose and ‘b’ carbon of fructose.
(d) ‘f’ carbon of glucose and ‘f’ carbon of fructose.

Question. In both DNA and RNA, heterocylic base and phosphate ester linkages are at –
(a)  C’₅ and C’₁ respectively of the sugar molecule
(b)  C’₁ and C’₅ respectively of the sugar molecule
(c)  C’₂ and C’₅ respectively of the sugar molecule
(d) C’₅ and C’₂ respectively of the sugar molecule

Question. Sucrose in water is dextro-rotatory, [α]_D= + 66.4º. When boiled with dilute HCl, the solution becomes leavo-rotatory,[α]_D= –20º. In this process the sucrose molecule breaks
into
(a) L-glucose + D-fructose
(b) L-glucose + L-fructose
(c) D-glucose + D-fructose
(d) D-glucose + L-fructose

Question. Which of the following pairs represents anomers?

Question. Which one of the following statements is not true regarding (+) Lactose ?
(a) On hydrolysis (+) Lactose gives equal amount of D(+) glucose and D(+) galactose.
(b) (+) Lactose is a β-glycoside formed by the union of a molecule of D(+) glucose and a molecule of D(+) galactose.
(c) (+) Lactose is a reducing sugar and does not exhibit mutarotation.
(d) (+) Lactose, C₁₂H₂₂O₁₁ contains 8-OH groups.

Question. Which of the following statements is correct?
(a) Only the compounds following general formula C_x(H₂O)_y are carbohydrates.
(b) Acetic acid (CH₃COOH) having general formula C₂(H₂O)₂ falls in this category.
(c) Rhamnose having formula C₆H₁₂O₅ is a carbohydrate.
Though this is not according to general formula of carbohydrates.
(d) Chemically the carbohydrates may be defined as optically inactive polyhydroxy aldehydes or ketones.

Question. Cyclic structure of fructose resembles with
(a) pyran
(b) furan
(c) pyridine
(d) oxiran

Question. In the acetylation of glucose, which group is involved in the reaction
(a) CHO group
(b) >C = O group
(c) alcoholic OH group
(d) all of these

Question. The strongest form of intermolecular bonding that could be formed involving the residue of the amino acid valine is
(a) ionic bond
(b) hydrogen bond
(c) van der Waals interactions
(d) none of the above

Question. Which one of the following is the reagent used to identify glucose?
(a) Neutral ferric chloride
(b) Chloroform and alcoholic KOH
(c) Ammoniacal silver nitrate
(d) Sodium ethoxide

Question. The function of enzymes in the living system is to
(a) transport oxygen
(b) provide energy
(c) provide immunity
(d) catalyse biochemical reactions

Question. Which one of the following sets of monosaccharides forms sucrose?
(a) α–D-Galactopyranose and α–D-Glucopyranose
(b) α–D-Glucopyranose and β–D-Fructofuranose
(c) β–D-Glucopyranose and α–D- Fructofuranose
(d) α–D-Glucopyranose and β–D-Fructopyranose