296 3 ON ke ead 10.1 Carbohydrates nt Lille] ‘Assertion (A) : Fructose is a reducing sugar. Reason (R) : Fructose does not reduce Fehling solution and Tollens’ reagent. (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A). (&) Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of the Assertion (A). (©) Assertion (A) is true, but Reason (R) is false. (d) Assertion (A) is false, but Reason (R) (Q)) is true. (2024) (ip) Assertion (A) : D(+)-Glucose is dextrorotatory. Reason R): Symbol'D’ representsits dextrorotatory nature. (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A). (b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A). (c) Assertion (A) is true, but Reason (R) is false. (a) Assertion (A) is false, but Reason (R) is true. (2023C) Which of the following is a non-reducing sugar? (a) Sucrose (b) Maltose (©) Glucose (@) Lactose (2023) (U) The glycosidic linkage involved in linking the glucose Units in amylose part of starch is (a) Cy—Cgatlinkage (b) C;—C,,B linkage (c) Cy—Cgalinkage (d) Cy —CgB linkage (2023) Which of the following sugar is known as dextrose? {a) Glucose (b) Fructose (c) Ribose (d) Sucrose (Term |, 2021-22) a-D(+) glucose and f-D(+) glucose are (a) geometrical isomers (b) enantiomers (c) anomers (d) optical isomers. (2020) (i) Assertion (A) : Sucrose is a non-reducing sugar. Reason (R) : Sucrose has glycosidic linkage. {a) Both Assertion (A) and Reason (R) are correct statements, and Reason (R) is the correct explanation of the Assertion (A). BsWiee CBSE Champion Chemistry Class 19 (b) Both Assertion (A) and Reason (R) are correct statements, but Reason (R) is not the correct ‘explanation of the Assertion (A). (c) Assertion (A) is correct, but Reason (R) is incorrect statement. (d) Assertion (A) is incorrect, but Reason (R) is correct statement. (2020) (in) = (1mark) ‘Name the disaccharide which on hydrolysis gives two molecules of glucose. (One word, 2020) 9. Write the name of linkage joining two monosaccharides. (One word, 2020) 410, What is the basic structural difference between glucose and fructose? (Delhi 2019) ) Write the structural difference between starch and cellulose. (Al 2019, 2016) Write the products obtained after hydrolysis of lactose. (Delhi 2019) 11. 12. OR Write the name of two monosaccharides obtained ‘on hydrolysis of lactose sugar. (Delhi 2016) Name a carbohydrate present in liver, muscles and brain (2019C) What are the hydrolysis products of sucrose ? (2019C) 13. 14, Define the following with an example Polysaccharides (1/3, 2018) Write the product when D-glucose reacts with cone HNO3. (1/3, 2018) ‘Which one of the following is a disaccharide: Starch. Maltose, Fructose, Glucose? (Delhi 2015) 60) Write the product obtained when D-glucose reacts with HJN—OH. (al 2015) Which one of the following is a monosaccharide starch, maltose, fructose, cellulase (Foreign 2015) (U 15. 16. 17. 18. 19. ! (2 marks) 20. Classify the following sugars into monosaccharides and disaccharides : Fructose, Lactose, Glucose, Maltose. (2024) Give the reaction of heating glucose with hydroxylamine. Presence of which group |= 21. ee confirmed by this reaction? (2023) (Au) 22, Define the following terms (i) Oligosaccharides . (il) Invert sugar (2020)(R) | ee PBiomolecules ja, Write the reactions showing the presence of following in the open structure of glucose (i) analdehyde group (i) a primary alcohol SEMIN (3 marks) 24, (a) What are the hydrolysis products of (i) Lactose, (i) Maltose? (b) Give the basic structural difference between (2020) starch and cellulose. (2023)( 1°) 25, Write the reaction of glucose with () HEN (i) Bry Gi) HI (2021 ¢) 26. Write chemical reactions to show that open structure of D-glucose contains the following : (i) Straight chain (i) Five alcohol groups (i) Aldehyde as carbonyl group. (Dethi 2019) (U'] What happens when D-glucose is treated with the following reagents? (a) Br, water (b) HN (0 (CHyCO),0 (al2019) (4 marks) Case Based Questions for life in both 28, Carbohydrates are essential plants and animals. Carbohydrates are used as storage molecules as starch in plants and glycogen in animals. Chemically they are polyhydroxy aldehydes or ketones. On the basis of their behaviour on hydrolysis, carbohydrates are classified as monosaccharides, oligosaccharides and polysaccharides. All monosaccharides are reducing sugars, ie,, they are oxidized by Tollens’ reagent and Fehling's solution, A monosaccharide like glucose is aldohexose and its molecular formula was found to be CyHy20,, After reacting with different reagents like HI, HJN—OH, bromine water, (CH3CO),0, ete. its structure was found to contain one aldehyde Broup, one primary alcoholic group, (-CH7OH) and four secondary alcoholic groups (»CHOH). Despite having the aldehyde group, glucose does not give some of the reactions of aldehyde group like Schiff's test, NaHSO; addition. This explains the existence of glucose in two cyclic hemiacetal forms which difer ony inthe configuration of the hydroxyl group Answer the following questions : (a) What are reducing sugars? (6) Classify the following into monosaccharide and disaccharide : Fructose, Sucrose, Lactose, Galactose (0 Name the polysaccharide which is known as ‘animal starch: Why is it called ‘animal starch’? 30. 297 OR () () Name the isomers of glucose which in the cyclic form differ only in the configuration of the -OH group at C-1. (ii) Presence of which functional group was detected when glucose reacted with Br, water? Carbohydrates are the major components of all living organisms. Sugars are carbohydrates. The major types of sugars include monosaccharides and disaccharides. The main difference between monosaccharides, disaccharides and polysaccharides is that monosaccharides are monomer of sugars and disaccharides are composed of two monomers, whereas polysaccharides are composed of a large number of monomers. Monosaccharides are single sugar molecules which act as the building blocks of disaccharides and polysaccharides. Disaccharides are also simple sugars. Disaccharides are classified intotwo groups according to their reducingstrength Reducing and Non-reducing sugars. When a polymer is formed from a monomer, a condensation reaction occurs that forms a glycosidic bond and water molecule is lost. Starch, glycogen and cellulose are examples of polysaccharides. Starch is found in many parts of plant cell and consists of amylose and amylopectin. Glycogen is the major carbohydrate storage product found in humans. It is present in liver, muscles and brain. Cellulose is the most abundant organic molecule on Earth, It makes up around 50% of all organic carbon. Answer the following questions : (a) Name the linkage which monosaccharide units in polysaccharides. (b) Carbohydrates are classified on the basis of their behaviour on hydrolysis. Write the hydrolysis products of sucrose. () Write two differences between amylose and amylopectin. (2024) CBQ connects OR (o) (i). What are reducing sugars? (ii) Sucrose is dextrorotatory but the mixture obtained after hydrolysis is laevorotatory. Why? (2023¢) Carbohydrates are optically active polyhydroxy aldehydes and ketones. They are also called saccharides. All those carbohydrates which reduce Fehling’s solution and Tollens’ reagent are referred to as reducing sugars. Glucose, the most important source of energy for mammals, is obtained by the hydrolysis of starch. Vitamins are accessory food factors required in the diet. Proteins are the polymers of a-amino acids and perform various298 structural and dynamic functions in the organisms. Deficiency of vitamins leads to many diseases. Answer the following : (a) The pentaacetate of glucose does not react with hydroxylamine. What does it indicate? (b) Why cannot vitamin C be stored in our body? (c)_ Define the following as related to proteins (i) Peptide linkage (ii) Denaturation OR (c)_ Define the following as related to carbohydrates : (i) Anomers (ii). Glycosidic linkage (2023) 10.2 Proteins L Mico 35. 36, 37. 38. The specific sequence in which amino acids are arranged in a protein is called its (a) primary structure (b) secondary structure (c) tertiary structure Q a (d) quaternary structure (2024)(R) {pleated sheet structure in proteins refers to (a) primary structure (b) secondary structure (©) tertiary structure (d) quaternary structure. (2023) ‘An achelix i a structural feature of (a) sucrose (b) polypeptides (©) nucleotides (4) starch. (2023, 2020) Complete the following analogy : Curdling of milk : A:: a-helix : B (a) A: Primary structure ,B : Secondary structure (b) A: Denatured protein, B : Primary structure (©) A: Secondary structure, B : Denatured protein (d) A: Denatured protein, B : Secondary structure (Term 1, 2021-22) (An) ‘Amino acids which cannot be synthesized in the body and must be obtained through diet are known as (a) acidic amino acids (b) essential amino acids (c)_ basic amino acids (d) non-essential amino acids. (Term I, 2021-22) The helix structure of proteins is stabilised by (a) peptide bond (b)_ hydrogen bond (©) disulphide bond (d)_ van der Waals’ forces. (2021C) Peptide linkage is present in (a) carbohydrates (b) vitamins (c) protein (4) rubber. (2020)(1!) Amino acids are (a) acidic (b) basic (c) amphoteric (d) neutral. (2020)(f1] (IEZED CRSE Champion Chemistry Class 19 39. Assertion (A) : Albumin is a globular protein, Reason (R) : Polypeptide chain coils around to give a straight chain (a) Both assertion (A) and reason (R) are correct statements, and reason (R) is the correct explanation of the assertion (A). (b) Both assertion (A) and reason (R) are correct statements, but reason (R) is not the correct explanation of the assertion (A) (©) Assertion (A) is correct, but reason (R) is incorrect statement. (d) Assertion (A) is incorrect, but reason (R) is correct statement. (2020) (1 mark) 40. What is the difference between a glycosidic linkage and a peptide linkage ? (2019) 0) 41. Define the following terms with a suitable example of each: (a) Anomers (b) Essential amino acids () Denaturation of protein (2019) 42. What is the difference between fibrous protein and globular protein? (1/3, Al 2017C, Delhi 2015) 43. Give one example each for fibrous protein and globular protein. (Al 2016) 44, Amino acids show amphoteric behaviour. Why? (al 2015) in) 45. What is the difference between acidic amino acids and basic amino acids? (Foreign 2015) BEND (2 marks) 46. Define the following terms {a) Denaturation of protein Qe (b) Invert sugar (2024) 8 47. Define denaturation of protein. What is the effect of denaturation on the structure of protein? (2023) 48, (a) Write chemical reaction to show that open structure of D-glucose contains the straight chai. (b) What type of linkage is responsible for the formation of protein? (2023) (An 49. Define the following with an example of each () Denatured protein (ii) Essential amino acids (2/3, 2018) 50. (a) Amino acids show amphoteric behaviour. Why? (b) Write one difference between a-helix and [pleated structures of proteins, (2/3, 2018) HEMI (3 marks) 51. Define the following terms (a) Glycosidic linkage (b) Primary structure of protein () Disaccharides eeesiomolecules (a) Write the product when D-glucose reacts with conc. HNO3, {v) Amino acids show amphoteric behaviour. Why? () Write one difference between achelix and frpleated structure of protein. (2023) Define proteins and classify them on the basis of their molecular shape. (2020¢) _. Differentiate between the following : (i) Amylose and Amylopectin {i) Peptide linkage and Glycosidic linkage {ii) Fibrous proteins and Globular proteins, (Delhi 2019) (Ev) Define the following terms as related to proteins : (i) Peptide linkage (ii) Primary structure (iii) Denaturation (Al 2015) BEE 6 aris) = Case Based Questions 56. Read the given passage and answer the questions number (i) to (v) that follow : 1x5=: Organic compounds containing amine as functional group are present in a vivid variety of compounds, namely amino acids, hormones, neurotransmitters, DNA, alkaloids, dyes, etc. Drugs including nicotine, morphine, codeine and heroin, etc. which have physiological ettects on humans also contain: amino group in one form or another. Amines are basic because of the presence of lone pair of electrons on nitrogen. Addition of nitrogen into an organic framework leads to the formation of two families of molecules, namely amines and amides. As chemistry students, we must appreciate the versatility of nitrogen, (i) What are amino acids ? (ii) Why are amino acids amphoteric ? (iii) Give one point of difference between acidic and basic amino acid. {iv) What are essential amino acids ? (V) Name the linkage formed when carboxyl end of one amino acid condenses with amino end of other amino acid. (2020) 10.4 Vitamins ra 57. Whi 7. Which of the following acids represents vitamin C? (a) Saccharic acid (b) Gluconic acid (0) Ascorbic acid @ (2024) (d) Benzoic acid WW mark) 5 8. Why vitamin C cannot be stored in our body? (Delhi 2016) 59, Writ le the name of vitamin whose deficiency causes ne deformities in children. (Delhi 2015) 299 60. Write the name of the vitamin whose deficiency causes bleeding of gums. (Foreign 2015) HMB (2 marks) 61. Define vitamins and classify them on the basis of (2020C) fi their solubility. HEMI (3 marks) 62. (a) What are the products of hydrolys’s of maltose ? (b) What type of bonding provides stability to a-helix structure of protein ? (c) Name the vitamin whose deficiency causes pernicious anaemia. (2019) 63. How are vitamins classified? Name the vitamin responsible for the coagulation of blood./Delhi 2015C) (4 marks) Case Based Questions 64, Certain organic compounds are required in small amounts in our diet but their deficiency causes specific disease. These compounds are called vitamins. Most of the vitamins cannot be synthesised in our body but plants can synthesised almost all of them. So they are ccnsidered as essential food factors. Howevers. the bacteria of the gut can produce some of the vitamins required by us. All Lite vitamins are generally available in our, diet. The term ‘vitamin’ was coined from the words vital + amine, since the earlier identified compounds had amino group. Vitamins are classified into two groups depending upon their solubility in water or fat namely-fat soluble vitamins and water soluble vitamins. ‘Answer the following questions (a) What is the other name of vitamin B,? (b) Name the vitamin whose deficiency causes increased blood clotting time. () Xerophthalmia is caused by the deficiency of which vitamin ? Give two sources of this vitamin. OR (c) Why can't vitamin C be stored in our body? Name the disease caused by the deficiency of this vitamin. 10.5 Nucleic Acids Ie) 65. Assertion (A) : Uracil base is present in DNA. Reason (R) : DNA undergoes self-replication (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A). (b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion(A). 2 (2024)300 (c)_ Assertion (A) is true, but Reason (R) is false. (a) Assertion (A) is false, but Reason (R) @ is true (2024) Assertion : The backbone of DNA RNA molecules is a chain consisting of heterocyclic base, pentose sugar and phosphate group. Reason ; Nucleotides and nucleosides mainly differ from each other in presence of phosphate group. (a) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A) (b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A) (c) Assertion (A) is true, but Reason (R) is false. (d) Assertion (A) is false, but Reason (R) is true. (2023) and The base which is present in DNA but not in RNA, is (a) cytosine (b) guanine (c) adenine (d) thymine. (Term 1, 2021-22)( A) Nucleic acids are polymer of (a) amino acids (b) nucleosides (c) nucleotides (d)_ glucose. (Term |, 2021-22, 2021C) Nucleosides are composed of (a) apentose sugar and phosphoric acid (b) anitrogenous base and phosphoric acid (©) anitrogenous base and a pentose sugar (@) a nitrogenous base, a pentose sugar and phosphoric acid. (Term |, 2021-22) (fi) areas (1 mark) Name the unit formed by the attachment of a base to 1 position of sugar. (2020C) Write the products obtained after hydrolysis of DNA. (2019) What is difference between a nucleoside and nucleotide? (2019, Delhi 2016) (HEED CBSE Champion Chemistry lag 55.12 What type of linkage is present in nucleic acids» (Al 2016) 7. BEN (2 marks) 74. (a) What happens when glucose reacts with nitric acid ? Write chemical equation (b) Write one structural difference Q between DNA and RNA (2024) 75. Write two differences between DNA and RNA (2023, 2019) (3 marks) 76. Give reasons for any 3 of the following observations (a) Penta-acetate of glucose does not react with hydroxylamine. (b) Amino acids behave like salts. (c). Water soluble vitamins must be taken regularly indiet. {d) The two strands in DNA are complementary to each other. (2023) Differentiate the following (i) Fibrous protein and Globular protein (ii). Essential amino acids and Non-essential amino acids (iii) DNA and RNA (20210) Give the plausible explanation for the following (a) Glucose doesn't give 2.4-DNP test. (b) The two strands in DNA are not identical but are complementary. (c) Starch and cellulose both contain glucose unit ‘as monomers yet they are structurally different. 77. 78. (2020) 79. Differentiate between following : (i) Amylose and Amylopectin (ii), Globular protein and Fibrous protein ra (2020) i) Nucleotide and Nucleoside Define the following terms : (a) Invert sugar (b) Native protein (c) Nucleotide 80. (2019) a err reece ES MiCc crny, ):Reducing sugars are those which can reduce solution and Tollens' reagent e.g., Glucose and Fehling Fructose. > {c):Glucose is correctly named as D(+)-glucose. ‘D’ before the name of glucose represents the configuration wnhereas (+) represents dextrorotatory nature of the molecule. 2, [a):sSucrose is a non-reducing sugar which on tydrolysis gives equimolar mixture of o-D(+)-glucose and p-D(-)fructose. Since, the reducing groups of glucose and fructose are involved in a glycosidic bond formation (C1 of arglucose and C2 of B-fructose), hence sucrose is non-reducing sugar. 4, (c):Starch is main storage polysaccharide of plants. It is a polymer of a-D-glucose and consists of two components - Amylose and Amylopectin. Amylose is held by Cy - Cg a-glycosidic linkage while amylopectin is formed by a - Cy - Cz and ot - Cy - Cg glycosidic linkage. 5, (2):Glucose is known as dextrose. 6. (cj: The pair of stereoisomers which differ only in the configuration of the hydroxyl group at C, are called anomers. A : H—C—OH HO——-C——-H 2 2| H: 7 OH 0 H a OH 3 HO. H HO H 4 4) H ‘OH H OH H 5 H 7 6 6 (CH,OH CH,OH a-D-(+)Glucose -D-(+)Glucose > Anomers differ in configuration at C-1 only. 7. {a):Sucrose is disaccharide and its two monosaccharides are held together by aglycosidic linkage. Since, the reducing groups of glucose and fructose are involved in glycosidic bond formation, therefore, sucrose isa non-reducing sugar. 8. Maltose 9. Glycosidic linkage 10. Glucose contains an aldehydic group while fructose contains a ketonic group. 14. The basic structural difference between starch and cellulose is of linkage between the glucose units. In starch, there is o-D-glycosidic linkage. Both the components of starch-amylose and amylopectin are polymer of a-D-glucose. On the other hand, cellulose is a linear polymer of B-D-glucose in which C, of one glucose unit is connected to C, of the other through B-D-glycosidic linkage. 42. Lactose on hydrolysis gives -D-glucose and B-D-galactose, 13. Carbohydrate is present in the form of glycogen in liver, muscles and brain. 14. Hydrolysis products of sucrose are glucose and fructose. 15. Carbohydrates which yield a large number of monosaccharide units on hydrolysis are called polysaccharides, eg,, cellulose. 16. On oxidation with nitric acid, D-glucose yields saccharic acid. CHO for i} HNO. (CHOH), —“—" (CHOM, | CH,0H COOH D-glucose D-saccharic acid amg > Oxidation of D-glucose takes place in presence of nitric acid. 17. Maltose is a disaccharide as it consists of two a-D-glucose units. 18. D-Glucose reacts with H,N—OH to give glucose oxime. CHO CH=N—OH I (CHOH),+NHjOH —> (CHOH), CH,OH CH,OH304 c=mmng ‘OTH;N—on #25 Sc=N—on e 19. Fructose is a monosaccharide because it cannot be hydrolysed to simpler polyhydroxy aldehydes or ketones. 20. Monosaccharides : Glucose and fructose Disaccharides : Lactose and maltose fies i |=NOH 24. (CHOM)y Moe (CHOH), i (Conf the presence ofa 4,08 ‘crteny ero) u,0H Gcmse use oxne 22. (i) These are the carbohydrates which on hydrolysis give 2-10 monosaccharides. For example, sucrose, lactose, maltose, etc. (i) An equimolar mixture of glucose and fructose, obtained by hydrolysis of sucrose in presence of an acid or the enzyme invertase is called invert sugar. 23. (i) Glucose on oxidation with a mild oxidising agent like bromine water gives gluconic acid containing CBSE Chambon Chemisty Ch 51 the same six carbon atoms as present in glucose. ry, indicates presence of aldehyde group, CHO COOH | Br,/H,0 (HOH +0] —— (CHoH, CH,OH CHOW Gluconicaci Ui) On acetylation with acetic anhydride, glucose ps a pentaacetate. This confirms that glucose contains fg OH groups. CHO CHO 0 (dHom, +5(CH3CO},0 —> a -o-t —CHy), CH,0H Hp—O—C—CH, Glucose § Glucose pentaacetate *+5CHsCOOH ConcentApplied 2 —OH group reacts with acetic anhydride while aldehyde group does not react with anhydrides ° il R-OH+(CH,CO),0—> R—-O—C—CH, D- qolastese and @-! auucert and o-b- #) Ye baie abuselural tro! sboach “u mode ccllulexe made CHO onc 5) om, > roe” 25. (i) (CHOH), > (HOH, CH,OH CH,OH Ctucoseeynohyérin (il) D-Glucose gets oxidised to carboxylic acid (gluconic acid) on reaction with bromine water. cro coos Brvater IcHOH, ete. aon, CH40H CH,OH _-Gicose ucla (iil) On proionged heating with Hi, D-glucose forms orhexane. CHO | Ha. {CHOH), “> cH, —(CH,),—CH, buon pHevane Dlucose glucese Liye. De a ert, Ws Bo ar lle wae Pi eu [Topper’s Answer, 2023] 26. (i) hexane, Glucose when heated with red P and HI gives CHO, EH + CH,CH;CH,CH;CHsCHs vierane It indicates the presence of straight chain of six carbon atoms in glucose. (i On acetylation with acetic anhydride, glucose gives a pentaacetate. This confirms that glucose contains five ~OH groups. cro (HOH, +5(CHyCO),0 —> CH,OH CHO 9 Glucose | I oH —O~C—CH,)4+ 5CHsCOOH Glucose pentascetateGlucose 09 oxidation with a mild oxidising agent like A ie water Bes BUCOMic Acid containing the same Tarpon atoms 35 present in ghicose. This indicates A ecence of aldehyde group cHO coon 8eyH,0 CHOH), +(0) —=""_, (HOM, CH;OH cHLOH ‘Gluconic acid + (a) O-Glucose gets oxidised to carboxylic acid nic acid) 0n reaction with bromine water. cHO Goon water (HOH, > (CHOW), ad cH,OH CH,OH D.Glucose Gluconic acid CN A CHO. ie Non py) CHOM. > (CHOH, i ° Glucose yanobyarin =) Onacetyiation with acetic anhydride, glucose gives + pentaacetate. This confirms that glucose contains ye OH groups, cHO +5(CH;CO),0 ge (CH—-O—C— CHa), # SCHsCOOH Cy -O—F— chy ° ‘Glucose pentaacetate 2 (a) Reducing sugar are those carbohydrates which have free aldehydic or ketonic group i.e., they reduce Fehling's solution and Tollens’ reagent. e.g., Maltose and Lactose. (8) Monosaccharide : Fructose, Galactose Disaccharides : Sucrose, Lactose (0 Carbohydrate gets stored in animal body as slycogen. It is known as animal starch as its structure is sinilar to amylopectin (ie, starch) OR fl) Anomers ie., a-D-glucose and f-D-glucose fil Presence of aldehyde ie., -CHO group is detected enreaction of glucose with Br water. 28. (a) Glycosidic linkage. (b)_ The hydrolysis products of sucrose are u-D-glucose and B-D-fructose. 305 ‘ SINo ‘Amylopectin 1 tis a Iinear It is ahighly branched condensation polymer polymer in which of «-D-glucose in which -D-glucose is linked Cy of one glucose with Cy-C, linkage Unit is attached to Cy | and C)-C, linkage is of the other through present hetween two LBlcosidic linkage linear chains, Amylose 2. Itis water soluble. soluble in water. this oR (<) (The sugars which contain free aldehydic or ketonic Broup and reduce Fehling’s solution and Tollens' reagent are called reducing sugars, Ui)” Sucrose is dextrorotatory but after hydrolysis gives dextrorotatory glucose and laevorotatory fructose. Since the laevorotation of fructose (-92.4") is more than dextrorotation of glucose (+52.5°), the mixture is laevorotatory. 80. (a) Absence of free CHO group. (b) Vitamin C cannot be stored in our body because it is a water soluble vitamin and is readily excreted through urine. (9) (i) The —CONH— linkage between two amino acids is called peptide linkage. Ail) The loss of biological activity of a protein by Changing the pH, temperature due to disruption of the native structure of protein is called denaturation, During denaturation, secondary and tertiary structures of protein are destroyed but primary structure remains intact. OR (2) i) The pair of stereoisomers which differ only in the configuration of the hydroxyl group at C, are called anomers. (ii) A linkage between two monosaccharides units through oxygen atom is called glycosidic linkage. 31, (a):The sequence of amino acids in a polypeptide chain is called primary structure of proteins. 32. (bj:f:pleated sheet structure in proteins refers to secondary structure. 33. (b):o-Helix is a secondary structure of protein. 34, (d):Curdling of milk is an example of denatured protein and a-helix represents secondary structure of protein. 25. (b):Essential amino acids must be taken through diet as these cannot be synthesised in the body. 36, (b):Helix structure of proteins is stabilised by hydrogen bonds. 37. (c}:Peptide linkage is present in proteins.| called peptide linkage. 8. (c):Amino acid contains both basic (-NH3} and acidic group (COOH! hence. there are amphotericin nature, 59. (c)-Albumin is a globular protein, The chains of polypeptides coil around to give a spherical shape. 40. Peptide linkage is an amide linkage formed between COOH group of one camino acid and —NH> group ‘of the other amino acid by loss of 3 molecule of water whereas 2 linkage between two monosaccharides units through oxygen atom is called glycosidic linkage. 41. (a) The pair of stereoisomers which differ only in the configuration of the hydroxyl group at C; are called (b) Essential amino acids : Amino acids which cannot be synthesized in the body and must be obtained through diet are known as essential amino acids, eg. valine, leucine, et. (©). Denaturation : The loss of biological activity of a protein by changing the pH, temperature or by adding some salt due to disruption of the native structure of protein is called denaturation. During denaturation. secondary and tertiary structure of proteins destroyed but primary structure remains intact 42. Characteristic differences between globular and fibrous proteins can be given 35: Fibrous pote “S\No. Globular proteins 1 These arecross- These are linear linked proteins and condensation are condensation polymer. product of acidic and basic amino acids. a 2 These are soluble in These are insoluble in water, mineral acids water but soluble in and bases. strong acids and bases. A pile A ainde Wwkage is nahonsbe Femation el prota (HIDCHsecrmrchensn cy ny 2 These proteins have These are linear three dimensional polymers held folded structure. together by These are stabilised | intermolecular by internal bydrogen | hydrogen bonds, ¢; bonding.es.¢x8 ai silk a abumin, enzymes 43, Globular protein ~ Insulin Fibrous protein ~ Keratin 44, As amino acids have both acidic (carboxy! and basic groups (amino group) in the same mee they react with both acids and bases. Hence. they 7 amphoteric behaviour. cng ‘> Amphoteric compounds react oth with acids ang bases, Acidic amino acids are those which contain ‘numberof carboxy! groups as compared to amino Whereas basic amino acids are those which containg ‘more number of amino groups than carboxy! groups, 46, (a) The loss of biological activity of a protein by changing the pH, temperature due to the disruption gf the native structure of protein is called denaturation During denaturation, secondary and tertiary structure of protein are destroyed but primary structure remains intact. {b) An equimolar mixture of glucose and fructose, obtained by hydrolysis of sucrose in presence of an acid or the enzyme invertase is called invert sugar, 3s hydrolysis of sucrose brings about a change in the sign of rotation, from dextro (+) to laevo (-). 47. Disruption of native conformation of protein by changing its environment resulting in loss of biological -xtivity is known as denaturation of protein. Proteins are very sensitive to the action of heat change ‘of pH. presence of electrolytes and radiation (particulary short wavelengths). Whenever proteins are subjected to such changes in the surroundings, they undergo some structural changes leading to the disruption of three dimensional structure Thus, causes permanent loss of activity of proteins During denaturation, 2° and 3° structures are destroyed but 1° structure remains intact The ternalise n= hover on 0 4 glices ubih HI ateuy thet Paver qhun char etuelity the. [Topper's Answer, 2023] ——piomolecules 12 (The loss of biological activity of a protein by enanging the pH, temperature or by adding some salt due to disruption of the native structure of protein is called tenaturation urine denaturation, secondary and tertiary structure of proteins destroyed but primary structure remains intact fe normal shape of protein gets deformed because some ottydrogen bonds are broken ands referred as denatured proteins. 8 curing of milk, coagulation of egg white on paling et ii) Essential amino acids : Amino acids which cannot be {inthesizedin the body and must be obtained through diet St qnown as essential aminoacids, eg, valine, leucine, ee, = (a). Asaminoacids have bath acidic (carboxyl group) snd basic groups (amino group) in the same molecule, they react with both acids and bases. Hence, they show. amphoteric behaviour. io) Ince structure, intramolecular H-bonding takes whereas in pleated structure, intermolecular Febonding takes place Cap 2 acHelix is having coiled structure while f-pleated is rot planar but slightly pleated, eg, froin. 51. (@). The two monosaccharides are joined together by an oxide linkage formed by the loss of water molecule. such linkages called elycsii linkage HOH HOH H OH H HO OH ° HO, CH,OH OH H (b) Primary structure : The specific sequence in which the various amino acids present in a protein are linked to ‘one another is called its primary structure. Any change in the primary structure creates a different protein. (@ Disaccharides are the carbohydrates which on hydrolysis give two molecules of the same or different ‘monosaccharides. Their general formula is Cy,H7201+ In disaccharides, the two monosaccharides are joined together by glycosidic linkage. 52. (a) On oxidation with nitric acid, D-glucose yields saccharic acid. fo COOH cone i (cron STEHNOS, CHOW | CH,OH COOH Dose Dacha aid 307 (b) As amino acids have both acidic (carboxy group) and basic groups (amino group) in the same molecule, they react with both acids and bases. Hence, they show amphoteric behaviour. (2) Ina-helix structure, intramolecular H-bonding. takes place whereas in [pleated structure, intermolecular H-bonding takes place. 53. Proteins are the biomolecules of the living ‘system made up of nitrogenous organic compounds by condensation polymerisation of «-amino acids. On the basis of molecular structure, proteins are classified as (a) Fibrous proteins : In fibrous proteins, polypeptide cchains are parallel and are held together by hydrogen and disulphide bonds. These are insoluble in water, eg.. keratin and myosin, (b) Globular proteins : Globular proteins result when the Polypeptide chains coil around to give three dimensional ‘spherical shape. These are soluble in water, eg., insulin and albumin 54. (i) Amylose is a linear condensation polymer of a-D-glucose in which C, of one glucose unit is attached to Cz of the other through a-glycosidic linkage while amylopectin is a highly branched polymer in which o-D-glucose is linked with Cy-C, linkage and Cy-Cy linkage is present between two linear chains. (ii)_ Peptide linkage is an amide linkage formed between —COOH group of one a-amino acid and NH, group of the other amino acid by loss of a molecule of water whereas a linkage between two monosaccharides units through oxygen atom is called glycosidic linkage. (il) Characteristic differences between globular and fibrous proteins can be given as a S.No. | Globular proteins Fi 1. | These are cross- | These are linear linked proteins and | condensation are condensation | polymer. product of acidic and | basic amino acids, These are soluble in These are insoluble in | water, mineral acids _ water but soluble in strong acids and bases, 3. | These proteins have These are linear three dimensional polymers held folded structure. together by These are stabilised | intermolecular by internal hydrogen bonds,eg, | hydrogen bonding, | hair, silk. | eg, egg albumin, | enzymes | | 55. (i) Proteins are the polymers of a-amino acids linked by amide formation between carboxyl and amino group. This is called peptide linkage or peptide bond, e3..308 = ° o —NH—CH—C—NH—CH—C— | 7] L kod OR Peptidelinkoge (ii) Primary structure : The specific sequence in which the various amino acids present in a protein are linked te ‘one another is called its primary structure. Any change in the primary structure creates a different protein. (ii) Denaturation : The loss of biological activity of a protein by changing the pH, temperature or by adding some salt due to disruption of the native structure of protein is called denaturation. During denaturation, secondary and tertiary structure of proteins destroyed but primary structure remains intact. 56. (i) Organic compounds containing both amino (—NH;) and carboxyl (~COOH) functional groups are called amino acids. R-GA—COOH NH, (ii) As amino acids have both acidic (carboxyl group) ‘and basic groups (amino group) in the same molecule, they react with both acids and bases. Hence, they show amphoteric behaviour (i) Acidic amino acids are those which contain more number of carboxyl groups as compared to amino groups wheress basic amino acids are those which contains more number of amino groups than carboxyl groups. (iv) Amino acids which cannot be synthesized in the body and must be obtained through diet are known as essential amino acids, eg. valine, leucine, etc (\) Proteins are the polymers of «-amino acids linked by amide formation between carboxyl and amino group. This is called peptide linkage or peptide bond, €3. i —NH—CH—C—NH—CH—C— pecan R L R Peptide linkage 57. {c):The chemical name of vitamin Cis ascorbic acid. 58. Vitamin C is soluble in water and regularly excreted inurine and hence cannot be stored in body. 59. Vitamin D 60. Vitamin C 61. Organic compounds required in the diet in small amounts to perform specific biological functions for normal maintenance of optimum growth and health of the organism are called vitamins. Vitamins are classified into two groups depending upon their solubility in water or fat. (i) Fat soluble vitamins, (eg, vitamin A and D) (ii) Water soluble vitamins, (eg, vitamin B and C) 62. (a) Maltose #9455 _ Glucose + Glucose (6) chelix structure of protein stabilised by hydrogen bonding, (Vitamin Byz (IEEE CBSE Champion Chemistry Classy 63. Vitamins are clasifed into two groups depending upon their solubility in water or fat. (i) Fat soluble vitamins, (eg. vitamin A and D) {i)_ Water soluble vitamins, (eg, vitamin B and ¢) Vitamin K is responsible for the coagulation of blood, 64. (a) Vitamin B, is also called pyridoxit (b)_ Vitamin K deficiency causes increased blood clotting time. (c) Xerophthalmia is caused by the deficiency of vitamin A. Fish liver oil, carrots, butter and milk etc. are the source of vitamin A. OR (o)_ Vitamin Ciswater soluble vitamin. It mustbe supplied regularly in diet because they are readily excreted in urine and cannot be stored in our body. Scurvy (bleeding ‘gums) disease is caused by the deficiency of vitamin C 65. (d):Uracil base is present in RNA. 66, (b):Nucleoside contains pentose sugar and base whereas nucleotide contains pentose sugar, base as well as phosphate group. Nucleoside = Base + Sugar Nucleotide = Base + Sugar + Phosphate, 67. (d):Thymine is present in DNA but not in RNA, 68. (¢):Nucleic acids are polymer of nucleotides. 69. (¢):Nucleosides are composed of a pentose sugar and a nitrogenous base. cmm@ ‘2 Nucleotide = Nucleoside + Phosphoric acid 70. A.unit formed by attachment of base to 1” position of sugar is known as nucleoside. 71. Complete hydrolysis of DNA (or RNA) yields 2 pentose sugar, phosphoric acid and nitrogen containing heterocyclic compounds as bases. 72. Nucleoside contains pentose sugar, and base whereas nucleotide contains pentose sugar, base as well as phosphate group. Nucleoside = Base + Sugar Nucleotide = Base + Sugar + Phosphate qImniG 2 Nucleoside + Phosphate = Nucleotide 73. Phosphodiester linkage 74, (a) On oxidation with nitric acid, D-glucose yields saccharic acid, ioe COOH conctno, (HoH, SEENON (CHOI, | (CH,OH_ ‘COOH Deas Saccharica (b) The sugar in DNA is deoxyribose while that in RNA eeBiomolecules ig ribose, DNA has a double-stranded helical structure, while RNA has a single-stranded helical structure. 75, Structural differences between DNA and RNA. {i)__ The sugar in DNA is deoxyribose while that in RNA {ij)_ DNA has a double-stranded helical structure, while RNA has a single-stranded helical structure, Functional differences between DNA and RNA {i) DNA is the chemical basis of heredity and is responsible for maintaining the identity of different species. (i) RNAmolecules are responsible for protein synthesis but the message for the synthesis of a particular protein ispresent in DNA. amg > RNA is having one extra OH in its sugar unit, Also bases present in RNA are adenine, cytosine, uracil and guanine, while in DNA these are thyamine, cytosine, adenine and guanine, 76. (a) As glucose forms a six-membered ring in which =CHO group combines with ~OH group at C-5, penta- acetate of glucose does not react with hydroxylamine due to the absence of free CHO group. (b) Amino acids behave like salts rather than simple amines or carboxylic acids. This behaviour is due to the presence of both acidic (carboxyl group) and basic (amino groups) group in the same molecule. (q) Water soluble vitamins must be taken regularly in diet because they are readily excreted in urine and cannot be stored (except vitamin B 2) in our body. (4) The two strands in DNA are complementary to each other because the hydrogen bonds are formed between specific pairs of bases. Adenine forms hydrogen bonds with thymine whereas cytosine forms hydrogen bonds with guanine. 77. (i) Characteristic differences between globular and fibrous proteins can be given as: Fibrous proteins These are linear condensation polymer. | These are cross-linked proteins and are condensation product of acidic and basic ____ amino acids. These are insoluble 2. | These are soluble in water, mineral acids | in water but soluble and bases, in strong acids and | bases. 309 These are linear polymers held together by intermolecular hydrogen bonds. e.. hair, silk These proteins have three dimensional folded structure, | These are stabilised | by internal hydrogen | bonding, eg. e8@ | albumin, enzymes (il) Amino acids which cannot be synthesized in the body and must be obtained through diet are known as essential amino acids, eg., valine, leucine, etc. The amino acids, which can be synthesised in the body, are known as non-essential amino acids. (i) The sugar in DNA is deoxyribose while that in RNA is ribose. DNA has a double-stranded helical structure, while RNA has a single-stranded helical structure. 78. (a) Actually, glucose exists in the cyclic hemiacetal form with only a small amount (< 0.05%) of the open chain form. Since, the concentration of the open chain form is low and its reaction with 2,4-DNP is reversible, therefore, formation of 24-DNP derivative cannot disturb the equilibrium to regenerate more of the open chain form from the cyclic hemiacetal form and hence, does not give this test. 2 99.95% glucose exists in cyclic hemiacetal form. (b) The two strands in DNA molecule are held together, by the hydrogen bonds between purine base of one strand and pyrimidine base of the other and vice versa. Because of different sizes and geometries of the bases, the only possible pairing in DNA are G (guanine) and C (cytosine) through three H-bonds, ie, (C=G) andbetween A(adenine) and T (thymine) through two H-bonds (ie, A= 1). Due to this base-pairing principle, the sequence of bases in one strand automatically fixes the sequence of bases in the other strand. Thus, the two strands are complementary and not identical. (c)_ The basic structural difference between starch and cellulose is of linkage between the glucose units. In starch, there is a-D-glycosidic linkage. Both the components of starch-amylose and amylopectin are polymers of «-D- glucose. On the other hand, cellulose is a linear polymer of 8-D-glucose in which C1 of one glucose unit is connected to C4 of the other through [}-D-glycosidic linkage. 79. (i) Amylose ‘Amylopectin | 15-20% part of | 80-85% part of starch starch, |310 2. | Made up of linear chain polymers of a-D glucose with LL C1-C4 linkage. | 3. Water soluble Made up of branched polymers of -D glucose with C1-C4 and C1-C6 linkage between two chains | Water insoluble (ii) Characteristic differences between globular and fibrous proteins can be given as : _S.No. Globular proteins _ 1. | These are cross- linked proteins and _| condensation | are condensation polymer. | | product of acidic and | basic amino acids. _ | 2. | These are soluble in | These are insoluble in | water, mineral acids | water but solublein | ___ and bases. | strong acids and bases. | 3. "| These proteins have These are linear | three dimensional polymers held folded structure. together by | These are stabilised | intermolecular | | by internal hydrogen | hydrogen bonds,eg., | | bonding, e.g., €88 hair, silk. | albumin, enzymes. | (iii) Nucleoside contains pentose sugar, and base whereas nucleotide contains pentose sugar, base as well as phosphate group. Nucleoside = Base + Sugar Nucleotide = Base + Sugar + Phosphate __ Fibrous proteins ‘| These are linear 80. (a) An equimolar mixture of glucose and fructose, obtained by hydrolysis of sucrose in presence of an acid or the enzyme invertase is called invert sugar. (b) Native protein : Protein purified from natural source which includes blood, plasma from animal etc. (c) When nucleoside is linked to phosphoric acid at 5’-position of sugar moiety, we get a nucleotide. ~ a CBSE Sample Questions CBSE Ch CHO COOH | 7 (HOH, HHNOs . (CHOH), CH,OH Glucose COOH Saccharic a (B) 5. (a) The —OH group prese glucose molecule forms a six- —CHO group to form a cyclic hy glucose does not give a positi reagent in the Schiff’s test. (b) The carbonyl group prese 6. (a) Acetylation of glucc gives glucose pentaacetate w! of five —OH groups. Since, it € five —OH groups should be a atoms CHO (CHOH), Acetic Anhydride CH,OH (b) Glucose reduces Fehlin H oO NF i H-C-—OH HO-CH acu + 2,0 eee H-C-OH | CH,OH (a) CHO 1,