Carbohydrates are broadly classified into three groups — monosaccharides, oligosaccharides and polysaccharides. Monosaccharides are held together by glycosidic linkages to form disaccharides and polysaccharides. An important monosaccharide glucose was assigned an open chain structure on the basis of...
CBSE CLASS 12 • CHEMISTRY • CHAPTER 10
Biomolecules
202 distinct questions across 251 board paper set appearances (2022–2026).
Assertion (A) : When glucose is added to water, an elevation in boiling point is observed.
Reason (R) : The lowering of vapour pressure causes elevation in the boiling point.
Assertion (A) : Vitamin C cannot be stored in our body.
Reason (R) : Vitamin C is fat soluble and is excreted from the body in urine.
Carbohydrates are optically active polyhydroxy aldehydes or ketones or the compounds which produce such units on hydrolysis. They have been broadly classified into three groups — monosaccharides, oligosaccharides and polysaccharides. The carbohydrates may also be classified as either reducing or non...
Assertion (A) : Glucose gets oxidized to six carbon gluconic acid on reaction with bromine water.
Reason (R) : The carbonyl group is absent in the open chain structure of glucose.
Identify the polysaccharide among the following :
(A) Fructose (B) Maltose
(C) Glucose (D) Cellulose
The polypeptide chain in a protein has amino acids linked with each other in a specific sequence. This specific sequence of amino acids is called :
(A) Primary structure of protein
(B) Secondary structure of protein
(C) Tertiary structure of protein
(D) Quaternary structure of protein
In the Haworth structure of the following carbohydrate, various carbon atoms have been numbered. The anomeric carbon is numbered as :
(A) 1
(B) 2
(C) 3
(D) 5
What is meant by essential amino acids ? Why are amino acids amphoteric in nature ?
Ribose and 2-deoxyribose have an important role in biology. Among the most important derivatives are those with phosphate groups attached at the 5 position. Mono-, di- and tri-phosphate forms are important, as well as 3-5 cyclic monophosphates. Purines and pyrimidines form an important class of comp...
Carbohydrates are polyhydroxy aldehydes or ketones that represent enormous structural diversity in terms of the arrangement of atoms in space, resulting in hundreds of stereoisomers. Although the chemical properties of most stereoisomers may not be very different, their metabolic rate and utilizatio...
The $\alpha$-amino acids are the building blocks of proteins. All $\alpha$-amino acids exist as zwitter ion due to which they show amphoteric behaviour. All amino acids are joined through peptide bond. Proteins are broadly classified as globular proteins and fibrous proteins. Globular proteins are w...
Reduce carbohydrates, increase protein to check diabetes, older people may need greater carbohydrates reduction. An average Indian derives $61 - 64%$ of energy from consumption of food rich in carbohydrates. A study published in the Journal of Diabetes Care has recommended reducing this to $49 - 56%...
(a) (i) How are carbohydrates stored in animal body ? Mention any one organ where they are present.
(ii) What is the basic structural difference between starch and cellulose ?
OR
(b) Differentiate between :
(i) Peptide linkage and Glycosidic linkage
(ii) Nucleoside and Nucleotide
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 in diet. (d) The two strands in DNA are complimentary to each other.
(a) (i) Name any two bases which are common to both DNA and RNA. (ii) Which vitamin deficiency causes : (1) Bone deformities in children ? (2) Pernicious anaemia ? OR (b) (i) Why do amino acids show amphoteric behaviour ? (ii) What happens when $\text{D-Glucose}$ is treated with hydroxylamine ?
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 disaccharide...
Proteins are polymers of $\alpha$-amino acids which are joined to each other by :
(A) Covalent Bond
(B) Peptide Bond
(C) Glycosidic Bond
(D) Coordinate Bond
The base which is present in DNA but not in RNA is :
(A) Guanine
(B) Cytosine
(C) Thymine
(D) Adenine
Living systems are made up of various complex biomolecules like carbohydrates, proteins, nucleic acids, lipids, etc. Proteins and carbohydrates are essential constituents of our food. In addition, some simple molecules like vitamins and mineral salts also play an important role in the functions of o...
(a) What are the products obtained on hydrolysis of sucrose ?
(b) What are essential amino acids ?
Functional groups present in amino acids are :
(A) $-\text{NH}_2$ and $-\text{OH}$
(B) $-\text{OH}$ and $-\text{COOH}$
(C) $-\text{COOH}$ and $-\text{NH}_2$
(D) $-\text{NH}_2$ and $-\text{SO}_3\text{H}$
Which of the following aqueous solutions will have the highest freezing point ?
(A) $1.0\text{ M KCl}$
(B) $1.0\text{ M Na}_2\text{SO}_4$
(C) $1.0\text{ M Glucose}$
(D) $1.0\text{ M AlCl}_3$
How do you explain the following ?
(a) Presence of an aldehydic group in glucose.
(b) Presence of five $-\text{OH}$ groups in glucose.
Give one point of difference between the following :
(a) Starch and Cellulose
(b) Primary and Secondary structure of protein
Proteins are the most abundant biomolecules of the living system. Proteins are the polymers of about twenty different $\alpha$-amino acids which are linked by peptide bonds. Ten amino acids are called essential amino acids. In zwitter ionic form, amino acids show amphoteric behaviour as they react b...
Assertion (A) : Maltose is a reducing sugar.
Reason (R) : Maltose is composed of two glucose units in which C-1 of one glucose unit is linked to C-4 of another glucose unit.
The particles in the nucleus of the cell, responsible for heredity, are called chromosomes which are made up of proteins and another type of biomolecules called nucleic acids. These are mainly of two types, DNA and RNA. Nucleic acids on hydrolysis yield a pentose sugar, phosphoric acid and nitrogen ...
The glycosidic linkage involved in linking the glucose units in amylase part of starch is : (a) $\text{C}_1 - \text{C}_6$ $\alpha$ linkage (b) $\text{C}_1 - \text{C}_6$ $\beta$ linkage (c) $\text{C}_1 - \text{C}_4$ $\alpha$ linkage (d) $\text{C}_1 - \text{C}_4$ $\beta$ linkage
An $\alpha$-helix is a structural feature of : (a) Sucrose (b) Starch (c) Polypeptides (d) Nucleotides
(a) Write chemical reaction to show that open structure of D-glucose contains the straight chain. (b) What type of linkage is responsible for the formation of protein ?
(a) What are the hydrolysis products of (i) Lactose, (ii) Maltose ?
(b) Give the basic structural difference between starch and cellulose.
Living systems are made up of various complex biomolecules like carbohydrates, proteins, nucleic acids, lipids, etc. Carbohydrates are optically active polyhydroxy aldehydes or ketones or molecules which provide such units on hydrolysis. They are broadly classified into three groups — monosaccharide...
Which of the following solutions will have the lowest freezing point in water ?
(A) $0.1\text{ M Glucose}$
(B) $0.1\text{ M CaCl}_2$
(C) $0.1\text{ M KCl}$
(D) $0.1\text{ M Urea}$
The deficiency of which of the following vitamins causes increased fragility of red blood cells and muscular weakness :
(A) Vitamin A
(B) Vitamin K
(C) Vitamin E
(D) Vitamin D
Assertion (A) : The pentaacetate of glucose does not react with $\text{H}_2\text{N}-\text{OH}$.
Reason (R) : It indicates the presence of free $-\text{CHO}$ group in glucose.
Differentiate between the following :
(i) Peptide linkage and Glycosidic linkage
(ii) Essential amino acids and Non-essential amino acids
Write the reactions of D-Glucose with the following :
(a) $\text{HI}$
(b) $\text{Br}_2$ water
(c) $\text{Conc. HNO}_3$
An example of non-reducing sugar is
(A) Glucose
(B) Sucrose
(C) Lactose
(D) Maltose
Assertion (A) : The two strands of DNA are complementary to each other.
Reason (R) : The hydrogen bonds are formed between specific pairs of bases.
Differentiate between the following :
(i) Acidic amino acids and basic amino acids
(ii) Nucleotide and Nucleoside
Define the following terms :
(a) Anomers
(b) Invert sugar
(c) Glycosidic linkage
In the ring structure of fructose, the anomeric carbon is
(A) $\text{C} - 1$
(B) $\text{C} - 2$
(C) $\text{C} - 3$
(D) $\text{C} - 5$
Assertion (A) : The pentaacetate of glucose does not react with $\text{H}_2\text{N} - \text{OH}$.
Reason (R) : It indicates the absence of free $-\text{CHO}$ group in glucose.
Differentiate between the following :
(i) Fibrous protein and Globular protein
(ii) Peptide linkage and Phosphodiester linkage
The base which is present in DNA but not in RNA is :
(A) $\text{Guanine}$
(B) $\text{Cytosine}$
(C) $\text{Thymine}$
(D) $\text{Adenine}$
Proteins are polymers of $\alpha-\text{amino acids}$ which are joined to each other by :
(A) $\text{Covalent Bond}$
(B) $\text{Peptide Bond}$
(C) $\text{Glycosidic Bond}$
(D) $\text{Coordinate Bond}$
Which of the following reactions is not explained by the open chain structure of glucose ?
(A) Glucose on prolonged heating with $\text{HI}$ forms n-hexane.
(B) Glucose reacts with hydroxylamine to form an oxime.
(C) Glucose gets oxidized to gluconic acid on reaction with bromine water.
(D) Glucose ...
28. (A) Define the following term :
(a) Reducing sugar
(b) Differentiate between the following :
(i) Fibrous proteins and globular proteins
(ii) Nucleotide and nucleoside
OR
(B) Write the reaction of glucose with the following :
(a) $\text{H}_2\text{N} - \text{OH}$
(b) $(\text{CH}_3\text{CO}...
Which of the following reactions is not explained by the open chain structure of glucose ?
(A) Glucose on prolonged heating with HI forms n-hexane.
(B) Glucose reacts with hydroxylamine to form an oxime.
(C) Glucose gets oxidized to gluconic acid on reaction with bromine water.
(D) Glucose exists in...
28. (A) (a) Define the following terms :
(i) Denaturation as related to proteins
(ii) Oligosaccharides
(b) On the basis of structure differentiate between Amylose and Amylopectin.
OR
(B) (a) What products would be formed when a nucleotide from DNA containing thymine is hydrolysed ?
(b) How wil...
Which of the following reactions is not explained by the open chain structure of glucose ?
(A) Glucose on prolonged heating with $ ext{HI}$ forms n-hexane.
(B) Glucose reacts with hydroxylamine to form an oxime.
(C) Glucose gets oxidized to gluconic acid on reaction with bromine water.
(D) Glucose e...
$60\text{ g}$ of glucose is dissolved in $250\text{ g}$ of water. Calculate the freezing point of this solution.
(molar mass of glucose $= 180\text{ g mol}^{-1}$, $K_f$ for water $= 1.86\text{ K kg mol}^{-1}$)
(A) (a) Define the following terms :
(i) Invert Sugar
(ii) Polysaccharides
(b) On the basis of structure differentiate between fibrous and globular proteins.
OR
(B) (a) Why is glycogen known as animal starch ?
(b) Differentiate between essential amino acids and non-essential amino acids.
(c) ...
Assertion (A) : Sucrose is a non-reducing sugar.
Reason (R) : A free aldehydic functional group is present in sucrose.
What are essential amino acids ? Why are amino acids amphoteric in nature ?
In the ring structure of fructose, the anomeric carbon is :
(A) C2
(B) C3
(C) C4
(D) C1
(a) What are essential amino acids ? How do you explain the amphoteric behaviour of amino acids ?
OR
(b) Define the following terms :
(i) Peptide linkage
(ii) Nucleotide
Carbohydrates are optically active polyhydroxy aldehydes or ketones or molecules that provide such units on hydrolysis. They are broadly classified into three groups : monosaccharides, oligosaccharides and polysaccharides. Monosaccharide units are held together by glycosidic linkages to form disacch...
(b) (i) Classify the following into monosaccharides and disaccharides : Fructose, Lactose, Glucose, Maltose
(c) Name the linkage which joins two monosaccharide units.
On hydrolysis, which of the following carbohydrates gives only glucose ?
(A) Sucrose
(B) Galactose
(C) Lactose
(D) Maltose
How do you explain the following ?
(a) Presence of a straight chain in glucose
(b) Presence of five $- ext{OH}$ groups in glucose which are attached to different carbon atoms
On hydrolysis, which of the following carbohydrates gives only glucose ?
(A) Starch
(B) Sucrose
(C) Lactose
(D) Galactose
How do you explain the following ?
(a) Presence of a carbonyl group in glucose
(b) Presence of five $- ext{OH}$ groups in glucose
(a) Write the name of basic building units of proteins and nucleic acids. How can you differentiate between Fibrous and Globular proteins on the basis of their structures ?
(b) (i) What products would be formed when a nucleotide from DNA containing thymine is hydrolyzed ?
(b) (ii) Write one structural difference between DNA and RNA.
(c) Give one example each of a fat-soluble vitamin and a water-soluble vitamin.
On hydrolysis, which of the following carbohydrates gives only $\beta$-glucose ?
(A) Starch
(B) Sucrose
(C) Maltose
(D) Cellulose
How do you explain the following ?
(a) Presence of an aldehyde group in glucose
(b) Presence of a primary alcoholic group in glucose
Nucleic acids are polymers of :
(A) amino acids
(B) nucleosides
(C) nucleotides
(D) pentose sugar
What are the hydrolysis products of the following ?
(a) Lactose
(b) DNA containing Thymine
Which of the following is a water-soluble vitamin ?
(A) \text{Vitamin K}
(B) \text{Vitamin A}
(C) \text{Vitamin B}
(D) \text{Vitamin D}
Each polypeptide in a protein has amino acids linked with each other in a specific sequence and it is this sequence of amino acids that is said to be :
(A) primary structure of proteins
(B) secondary structure of proteins
(C) tertiary structure of proteins
(D) quaternary structure of proteins
What is the effect of denaturation on the structure of proteins ? What are the common types of secondary structures of proteins ?
Answer the following questions :
(a) How do you explain the following ?
(i) Presence of a carbonyl group in glucose
(ii) Presence of five $-\text{OH}$ groups in glucose which are attached to different carbon atoms.
(b) What type of carbohydrates are called reducing sugars ?
(c) (i) In $\text{D}(+)\t...
Assertion (A) : $ ext{D} (+) - ext{Glucose}$ is dextrorotatory in nature.
Reason (R) : $(+)$ represents dextrorotatory nature and $ ext{D}$ represents the configuration.
(a) Write any two fat soluble vitamins.
(b) How will you confirm the presence of five $-\text{OH}$ groups in a glucose molecule, which are attached to different carbon atoms ?
Assertion (A) : $\text{D } (+) \text{ - Glucose}$ is dextrorotatory in nature.\nReason (R) : $(+)$ represents dextrorotatory nature and $\text{D}$ represents the configuration.
(a) Write the hydrolysis products of lactose.
(b) What are non-essential amino acids ?
(a) Name two water-soluble vitamins.
(b) How will you prove the absence of free $-\text{CHO}$ group in the cyclic structure of glucose molecule ?
Assertion (A) : D (+) - Glucose is dextrorotatory in nature.
Reason (R) : (+) represents dextrorotatory nature and D represents the configuration.
(a) Name the disease caused by the deficiency of Vitamin A.
(b) How will you confirm the presence of carbonyl group as an aldehydic group in glucose ?
Functional groups present in amino acids are :
(A) $- ext{NH}_2$ and $- ext{OH}$
(B) $- ext{OH}$ and $- ext{COOH}$
(C) $- ext{COOH}$ and $- ext{NH}_2$
(D) $- ext{NH}_2$ and $- ext{SO}_3 ext{H}$
(a) Mention any two types of RNA molecules.
(b) How is glycogen different from starch ?
(c) Explain the $\beta$-pleated sheet structure of proteins.
(a) What is meant by invert sugar ?
(b) What happens when glucose reacts with nitric acid ? Write the reaction involved.
(c) Name the disease caused by the deficiency of $\text{Vitamin B}_1$.
(a) Mention any two bases present in DNA.
(b) Which component of starch is an unbranched chain polymer of $\alpha - \text{D} - (+)$ glucose ? Write its one characteristic feature.
(c) Write the name of the linkage present between amino acids. How is it represented ?
(a) What are anomers ? Explain.\n(b) What happens when glucose reacts with hydroxylamine ? Write the reaction involved.\n(c) Name the disease caused by the deficiency of $\text{Vitamin B}_{12}$.
(a) Write two structural differences between DNA and RNA.
(b) Which component of starch is a branched chain polymer of $\alpha-\text{D}-(+)$ glucose ? Write its one characteristic feature.
(c) Which types of bonds hold the polypeptide chains in fibrous proteins ?
(a) Define 'Denatured Protein' with an example.
(b) What happens when glucose reacts with $\text{HCN}$ ? Write the reaction involved.
(c) Name the disease caused by the deficiency of Vitamin C.
Which of the following is laevorotatory in nature :
A. alpha D $-$ glucose
B. beta $- ext{D}$- glucose
C. beta-$ ext{D}$- fructose
D. sucrose
Assertion (A): Starch forms colloidal solution with water.\nReason (R): Starch contains 80-85% of amylopectin which is insoluble in water.\nSelect the most appropriate answer from the options given below:\nA. Both A and R are true, and R is the correct explanation of A.\nB. Both A and R are true, an...
Attempt either A or B
A. Answer the following questions:
I. Identify and give any one point of difference between the protein present in the hair and protein present in egg albumin.
II. Both glucose and sucrose have aldehydic group, then why does only glucose reduces Fehling's Reagent and not sucro...
The deficiency of which vitamin causes pernicious anaemia ?
(A) $\text{Vitamin B}_{12}$
(B) $\text{Vitamin B}_6$
(C) $\text{Vitamin B}_1$
(D) $\text{Vitamin B}_2$
Define the following terms as related to proteins :
(a) Peptide linkage
(b) Denaturation
Differentiate between the following :\n(a) Fibrous protein and Globular protein\n(b) Nucleotide and Nucleoside\n(c) Essential amino acids and Non-essential amino acids
Which of the following is a polysaccharide ?
(A) Maltose
(B) Glucose
(C) Cellulose
(D) Sucrose
What is the effect of denaturation on the structures of protein ? Give one example each of fibrous protein and globular protein.
Carbohydrates are optically active polyhydroxy aldehydes or ketones or molecules which provide such units on hydrolysis. They are broadly classified into three groups — monosaccharides, oligosaccharides and polysaccharides. Monosaccharides are held together by glycosidic linkage to form disaccharide...
Which of the following aqueous solutions will have the highest freezing point ?
(A) $1\cdot0\text{ M KCl}$
(B) $1\cdot0\text{ M Na}_2\text{SO}_4$
(C) $1\cdot0\text{ M Glucose}$
(D) $1\cdot0\text{ M AlCl}_3$
(a) Name the type of linkage responsible for the formation of proteins from $\alpha$-amino acids.
(b) Write any two differences between $\text{DNA}$ and $\text{RNA}$.
(a) Name the vitamin whose deficiency causes pernicious anaemia.
(b) Write any two differences between globular and fibrous proteins.
(a) Name the vitamin which is responsible for coagulation of blood.
(b) What is meant by denaturation of protein ? Give an example.
Pyranose ring of glucose is formed due to the reaction between :
(A) $ ext{C}_1$ and $ ext{C}_3$
(B) $ ext{C}_1$ and $ ext{C}_5$
(C) $ ext{C}_1$ and $ ext{C}_4$
(D) $ ext{C}_1$ and $ ext{C}_2$
Furanose ring of fructose is formed due to reaction between :
(A) $ ext{C}_1$ and $ ext{C}_5$
(B) $ ext{C}_2$ and $ ext{C}_5$
(C) $ ext{C}_1$ and $ ext{C}_4$
(D) $ ext{C}_1$ and $ ext{C}_2$
$\alpha$-D-glucose and $\beta$-D-glucose differ from each other with respect to the :
(A) size of the hemiacetal ring
(B) configuration at the $\text{C}_2$ carbon
(C) number of $-\text{OH}$ groups
(D) configuration at the $\text{C}_1$ carbon
How do you explain the following ?
(a) Presence of an aldehydic group in glucose.
(b) Presence of five $- ext{OH}$ groups in glucose.
(b) Why do amino acids show amphoteric behaviour ?
(c) (i) How can you differentiate between Fibrous protein and Globular protein ?
(c) (ii) Write the names of two different secondary structures of proteins.
Which of the following solutions will have the highest boiling point in water ?
(A) $1% \text{KCl}$
(B) $1% \text{glucose}$
(C) $1% \text{urea}$
(D) $1% \text{CaCl}_2$
$\alpha$-helix structure refers to :
(A) primary structure of protein
(B) secondary structure of protein
(C) tertiary structure of protein
(D) quaternary structure of protein
Assertion ($A$) : Vitamin K can be stored in our body.
Reason ($R$) : Vitamin K is a water soluble vitamin.
The two strands in DNA are not identical but complementary. Explain. What products would be formed when DNA is hydrolysed ?
Write the reaction of D-Glucose with the following :
(a) $\text{HCN}$
(b) $\text{Br}_2$ water
(c) $(\text{CH}_3\text{CO})_2\text{O}$
'Scurvy' is caused due to the deficiency of :
(A) Vitamin A
(B) Vitamin $ ext{B}_2$
(C) Vitamin C
(D) Vitamin D
Write two differences between Amylose and Amylopectin components of starch.
Differentiate between :
(a) Essential amino acids and Non-essential amino acids
(b) Peptide linkage and Glycosidic linkage
(c) Fibrous protein and Globular protein
Deficiency of vitamin $\text{B}_1$ causes the disease :
(A) Convulsions
(B) Beri-Beri
(C) Fissuring at corners of mouth and lips (Cheilosis)
(D) Muscular weakness
Assertion (A) : Vitamin C cannot be stored in our body.
Reason (R) : Vitamin C is water soluble and excreted in urine.
Write two differences between DNA and RNA.
Write the reaction of D-Glucose with the following :
(a) $ ext{HCN}$
(b) $ ext{Br}_2 ext{ water}$
(c) $( ext{CH}_3 ext{CO})_2 ext{O}$
Glucose on reaction with $ ext{Br}_2$ water gives :
(A) Gluconic acid
(B) Hexanoic acid
(C) Saccharic acid
(D) Glycolic acid
Glucose on reaction with nitric acid gives :
(A) Gluconic acid
(B) Hexanoic acid
(C) Saccharic acid
(D) Glycolic acid
Glucose on reaction with hydrogen iodide gives :
(A) Gluconic acid
(B) n-Hexane
(C) Saccharic acid
(D) Hexanoic acid
Which of the following contains only $\text{}\beta\text{-D- glucose}$ as its monosaccharide unit:<br><br>a. Sucrose<br>b. Cellulose<br>c. Starch<br>d. Maltose
Assertion (A) Glucose does not form the hydrogensulphite addition product with $\text{NaHSO}_3$.
Reason (R): Glucose exists in a six-membered cyclic structure called pyranose structure.
Select the most appropriate answer from the options given below:
a. Both A and R are true and R is the correct ex...
Which of the following statements is not true about glucose ?
(A) It is an aldohexose.
(B) It gives 2,4-DNP test.
(C) It is present in pyranose form.
(D) On heating with HI it forms n-hexane.
What happens when D-glucose is treated with the following reagents :
(a) $\text{HCN}$
(b) $\text{Br}_2$ water
Organic compounds containing amine as functional group are present in a vivid variety of compounds, namely amino acids, hormones, neurotransmitters, DNA, dyes, etc. Amino acids are classified as acidic, basic or neutral depending upon the relative number of amino and carboxyl groups in their molecul...
The vitamin which plays an important role in coagulating blood is :
(A) Vitamin A
(B) Vitamin E
(C) Vitamin D
(D) Vitamin K
Give reaction of glucose with the following :
(a) $\text{HCN}$
(b) Conc. $\text{HNO}_3$
'Night-Blindness' is caused by the deficiency of Vitamin :
(A) B
(B) C
(C) K
(D) A
Write the reactions of glucose with :
(a) $\text{H}_2\text{N} - \text{OH}$
(b) $\text{Br}_2$ water
'Scurvy' is caused by the deficiency of vitamin :
(A) E
(B) A
(C) C
(D) D
Write the reactions of glucose with : (a) HI (b) ($\text{CH}_3\text{CO})_2\text{O}$
(a) What are essential amino acids?
(b) What is meant by zwitter ionic form of amino acids?
(c) (i) Give one example each for Fibrous protein and Globular protein.
(ii) What type of linkages hold monomers of proteins together?
OR
(c) (i) What is the structural feature which characterises a reducing ...
Write the reaction of glucose with :
(a) $\text{HI}$
(b) $\text{Br}_2$ water
(a) Write two functions of DNA.
(b) What products will be formed when a nucleotide from DNA containing Adenine is hydrolyzed ?
(c) (i) What are nucleic acids ? What is the difference between nucleotide and nucleoside ?
(c) (ii) Give one similarity and one difference between DNA and RNA.
Write the reactions of glucose with
(a) $\text{HCN}$
(b) $\text{Conc. HNO}_3$
Assertion (A) : Maltose is a non-reducing sugar.
Reason (R) : Maltose is composed of two glucose units in which C-1 of one glucose unit is linked to C-4 of another glucose unit.
Write the reaction of glucose with :
(a) HI
(b) $\text{Br}_2$ water
Nucleic acids are the polymers of :
(A) Nucleotides
(B) Nucleosides
(C) Bases
(D) Sugars
Do any five of the following:
(a) Pentaacetate of glucose does not react with hydroxylamine. Give reason.
(b) Why do amino acids behave like salts?
(c) Why must water soluble vitamins be taken regularly in diet? (d) Why are the two strands in DNA complementary to each other? (e) What happens when D-glucose is heated with HI? (f) What is meant by glycosidic linkage? (g) What are enzymes?
An $\alpha$-helix is a structural feature of
(a) Sucrose
(b) Polypeptides
(c) Nucleotides
(d) Starch
Define denaturation of protein. What is the effect of denaturation on the structure of protein ?
The glycosidic linkage involved in linking the glucose units in amylase part of starch is :
(a) $\text{C}_1-\text{C}_6 \ \alpha \text{ linkage}$
(b) $\text{C}_1-\text{C}_6 \ \beta \text{ linkage}$
(c) $\text{C}_1-\text{C}_4 \ \alpha \text{ linkage}$
(d) $\text{C}_1-\text{C}_4 \ \beta \text{ linkage}...
Which of the following is a non-reducing sugar ?
(a) Sucrose
(b) Maltose
(c) Glucose
(d) Lactose
(a) Write the product when D-glucose reacts with conc. $\text{HNO}_3$.
(b) Amino acids show amphoteric behaviour. Why ?
(c) Write one difference between $\alpha$-helix and $\beta$-pleated structure of protein.
(a) DNA fingerprinting is used to determine paternity of an individual. Which property of DNA helps in the procedure?
(b) What structural change will occur when a native protein is subjected to change in pH?
When sucrose is hydrolysed the optical rotation values are measured using a polarimeter and are given in the following table:
| S.No. | Time (hours) | Specific Rotation |
|---|---|---|
| 1 | 0 | $+66.5^{\circ}$ |
| 2 | $\infty$ | $-39.9^{\circ}$ |
(a) Account for the two specific rotation values.
...
Proteins are polymers of
(a) Nucleic acids
(b) Amino acids
(c) Monosaccharides
(d) Amines
(a) What is the difference between a nucleoside and nucleotide ? (b) What products would be formed when a nucleotide from DNA containing thymine is hydrolysed ?
Carbohydrates are optically active polyhydroxy aldehydes and ketones. They are also called saccharides. All those carbohydrates which reduce Fehling's solution and Tollen's reagent are referred to as reducing sugars. Glucose, the most important source of energy for mammals, is obtained by the hydrol...
When D-glucose reacts with HI, it forms
(a) Gluconic acid
(b) n-hexane
(c) Saccharic acid
(d) Iodohexane
What are nucleic acids ? Why two strands in DNA are not identical but are complementary ?
The deficiency of which Vitamin causes rickets ? (a) Vitamin A (b) Vitamin B (c) Vitamin C (d) Vitamin D
Oligosaccharides on hydrolysis could yield :
(a) 3 to 9 monosaccharides
(b) 4 to 10 monosaccharides
(c) more than 10 monosaccharides
(d) 3 to 10 monosaccharides
On hydrolysis, which of the following carbohydrates gives only glucose ?
(a) Starch
(b) Fructose
(c) Lactose
(d) Sucrose
Which of the following vitamins is water soluble ?
(a) Vitamin A
(b) Vitamin D
(c) Vitamin E
(d) Vitamin C
Write the structure of product when D-Glucose reacts with the following : (any three) (a) $\text{HI}$ (b) Conc. $\text{HNO}_3$ (c) $\text{Br}_2$ water (d) $\text{HCN}$
A vitamin which plays a vital role in the clotting of blood is :
(a) Vitamin A
(b) Vitamin K
(c) Vitamin D
(d) Vitamin B
Write the structure of product when D-Glucose reacts with the following : (any three)
(a) HI
(b) Conc. $\text{HNO}_3$
(c) $\text{Br}_2$ water
(d) HCN
In the ring structure of glucose, the anomeric carbon is :
(a) C-2
(b) C-3
(c) C-4
(d) C-1
Deficiency of Vitamin B causes :
(a) rickets
(b) muscular weakness
(c) scurvy
(d) beri-beri
Write the structure of product when D-Glucose reacts with the following :
(any three)
(a) $\text{HI}$
(b) $\text{Conc. HNO}_3$
(c) $\text{Br}_2$ water
(d) $\text{HCN}$
Which of the following structures represents $\alpha$-D-glucose ?
(a) Image of cyclic structure (a)
(b) Image of cyclic structure (b)
(c) Image of cyclic structure (c)
(d) Image of cyclic structure (d)
On hydrolysis, which of the following carbohydrates gives only glucose ? (a) Maltose (b) Sucrose (c) Lactose (d) Galactose
Deficiency of which of the following vitamins causes Pernicious anaemia ? (a) Vitamin $\text{B}_1$ (b) Vitamin $\text{B}_2$ (c) Vitamin $\text{B}_6$ (d) Vitamin $\text{B}_{12}$
Which of the following structures represents $\alpha$-D-glucose?
On hydrolysis, which of the following carbohydrates gives glucose and fructose ? (a) Sucrose (b) Starch (c) Lactose (d) Maltose
The deficiency of which of the following vitamins causes Scurvy ? (a) Vitamin A (b) Vitamin $\text{B}_6$ (c) Vitamin C (d) Vitamin $\text{B}_{12}$
What is the difference between a glycosidic linkage and peptide linkage ?
Which amino acids are called essential amino acids ?
What are the common types of secondary structures of proteins ? Write any two forces which stabilise the secondary and tertiary structures of protein.
Define denaturation of protein with an example. During denaturation which structures of protein lose their biological activity ?
Which of the following structures represents $\alpha$-D-glucose ?
(a) Image containing chemical structure of glucose
(b) Image containing chemical structure of glucose
(c) Image containing chemical structure of glucose
(d) Image containing chemical structure of glucose
Hydrolysis of sucrose is called
(a) inversion
(b) hydration
(c) esterification
(d) saponification
Assertion (A) : Proteins are polymers of $\alpha$-amino acids connected by a peptide bond. Reason (R) : A tetrapeptide contains 4 amino acids linked by 4 peptide bonds.
Give the reaction of glucose with hydrogen cyanide. Presence of which group is confirmed by this reaction ?
Which of the following statements is not true about glucose ?
(a) It is an aldohexose.
(b) On heating with HI it forms n-hexane.
(c) It is present in pyranose form.
(d) It gives 2, 4 DNP test.
Give the reaction of glucose with acetic anhydride. Presence of which group is confirmed by this reaction ?
$\beta$-pleated sheet structure in proteins refers to
(a) primary structure
(b) secondary structure
(c) tertiary structure
(d) quaternary structure
Assertion (A) : The backbone of DNA and RNA molecules is a chain consisting of heterocyclic base, pentose sugar and phosphate group. Reason (R) : Nucleotides and nucleosides mainly differ from each other in presence of phosphate group.
Answer the following questions :
(a) Name the linkage which connects monosaccharide units in polysaccharides.
(b) Carbohydrates are classified on the basis of their behaviour on hydrolysis. Write the hydrolysis products of sucrose.
(c) Write two differences between Amylose and Amylopectin.
OR
(c) (i...
Assertion (A) : $\text{D (+)-Glucose}$ is dextrorotatory. Reason (R) : Symbol 'D' represents its dextrorotatory nature.
Assertion (A) : All monosaccharides are reducing sugars.
Reason (R) : They reduce Fehling's and Tollens' reagent.
(c) Write two differences between Amylose and Amylopectin.
OR
(c) (i) What are reducing sugars?
(ii) Sucrose is dextrorotatory but the mixture obtained after hydrolysis is laevorotatory. Why?
Assertion (A) : Glucose gets oxidised to six carbon carboxylic acid on reaction with bromine water.
Reason (R) : Glucose contains a ketonic group.
(b) Carbohydrates are classified on the basis of their behaviour on hydrolysis. Write the hydrolysis products of sucrose.
(c) Write two differences between Amylose and Amylopectin.
OR
(c) (i) What are reducing sugars?
(ii) Sucrose is dextrorotatory but the mixture obtained after hydrolysis is laevor...
Which one among the following bases is present in RNA but usually not in DNA ?
(a) Uracil
(b) Thymine
(c) Adenine
(d) Guanine
Assertion (A) : Sucrose is a non-reducing sugar.
Reason (R) : Sucrose has a glycosidic linkage.
Nucleic acids are the polymers of nucleotides which in turn consist of a base, a pentose sugar and phosphate group. Nucleic acids are responsible for the transfer of characters from parents to offsprings. There are two types of Nucleic acids — DNA and RNA. DNA is the chemical basis of heredity and h...
Given below are two statements labelled as Assertion (A) and Reason (R)
Assertion (A): Proteins are found to have two different types of secondary structures viz alpha-helix and beta-pleated sheet structure.
Reason (R): The secondary structure of proteins is stabilized by hydrogen bonding.
Select th...
Account for the following: a. There are 5 OH groups in glucose b. Glucose is a reducing sugar OR What happens when D – glucose is treated with the following reagents a. Bromine water b. $\text{HNO}_3$
Strengthening the Foundation: Chargaff Formulates His "Rules"
Many people believe that James Watson and Francis Crick discovered DNA in the 1950s. In reality, this is not the case. Rather, DNA was first identified in the late 1860s by Swiss chemist Friedrich Miescher. Then, in the decades following ...