KENDRIYA VIDYALAYA SANGATHAN AHMEDABAD REGION

MODEL QUESTION PAPER-2022-23

Time: 3 hrs. Class: 12 Marks: 70

Subject: CHEMISTRY (BIOMOLECULE)

General Instructions:
Read the following instructions
carefully.
a. There are 35 questions in this
question paper with internal choice.
b.SECTION Aconsists of :8 multiple-choice questions carrying 1 mark each.
C. SECTION B consists of 7 very short answer questions carrying 2 marks each.
d. SECTIONC consists of 5 short answer questions carrying 3 marks each.
e. SECTION D consists of 2 case-based questions carrying 4 marks each.
f. SECTION E consists of 3 long answer questions carrying 5 marks each.

SECTION-A

Which of the following carbohydrates does not satisfy the formula Cx(H;0)y?
1
a)Fructose
b) Glucose
c) Deoxyribose
d) Lactose

2 Which of the following is not a polysaccharide?

a) Cellulose
b) Stachyose
c) Starch

d) Glycogen monosaccharide units?

3 Sucrose consists of which of the following
a) Fructose, galactose
b) Fructose, glucose
c) Galactose, glucose
d Glucose, glucose_
Nucleotides are joined together by
c) glycosidic linkaged) phosphodiester linkage
a) peptide inkage b) disulphide linkage
is not true for glucose?
Which of the following statement
5
does not react with hydroxylamine to give oxime
a) The pentaacetate of glucose
for aldehyde
b) Glucose gives Schiff's test
in two crystalline a and ß forms
c) Glucose exists
d Glucose reacts with hydroxylamine toform oxime disaccharide. 1
through a bond to form a
6 Two monosaccharides are joined
a) ionic
b) peptide
c)glycosidic
d) phosphodiester
incorrect regarding maltose?
Which of the following is
glucopyranose units
a) It consists of two
b) It is a non-reducing sugar unit and Ca of the other unit
between C1 of one
c) Glycosidic bond
d)It is a disaccharide
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 8 Proteins are polymers of.
a) a-amino acids
b) B-amino acids
c) y-amino acids
d) 8-amino acids
9 Which of the following amino acids is optically inactiver
a) Glycine
b) Alanine
c) Lysine
d Valine
10 Enzymes are regarded as
a)biocatalysts
b) messengers
c) inhibitors
d) antibodies 1
11 Which of the following vitamin is soluble in water?
a) A
b)C
c) D
d)E
12 The following compound is a component of which ofthe following?
CH2OH OH

) RNA
A OH H
b) DNA
c) Adenine
d) Guanine
13 In nucleic acids, the sequence is:
a) Base sugar phosphate
b) Base phosphate sugar
c) Phosphate sugar - base

d Sugar-base-phosphate
14 Identify the saccharide from the Haworth projection shown below.
H2OH CH2OH
HO/ H OH
O-
OH H 9H
H OH H OH
a) Lactose
b) Maltose
c) Sucrose
d) Trehalose

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 Given below are tw statements labelled as Assertion (A) and Reason (R) 1
Assertion:-Uracil is present in DNA
Reason DNA undergoes replication
Select the most appropriate answer from the
options given below
a. Both A and R are true and R
is the correct explanation of A
b. Both A and R are true but R is not the
correct explanation of A
c. A is true but R is false.

d. A is false but R is true.

iven below are two statements labelled as Assertion (A) and Reason (R) 1

Assertion:- Insulin is globular protein.

Reason Globular Proteins are water soluble.
Select the most appropriate answer from the options given below
a. Both A and R are true and R is the correct explanation of A
b. Both A and R are true but R is not the correct explanation of A.
C. A is true but R is false.
d. A is false but R is true.
Given below are two statements labelled as Assertion (A) and Reason (R)
Assertion:-D(#)-Glucose is dextrorotatory in nature.
ReasonD' represents its dextrorotatory nature.
Select the most appropriate answer from the options given below:
a. Both A and R are true and R is the correct explanation of A
b. Both A and R are true but R is not the correct explanation of A.
c. A is true but R is false.
d. Ais false but Ris true. 1
below are two statements labelled as Assertion (A) and (R)
Reason
8 Given
Assertion :- In presence of enzyme, substrate molecule can be attacked by the reagent

effectively
Reason Active sites of enzymes hold the substrate molecule in a suitable position.
Select the most appropriate answer from the options given below:
a. Both A and R are true and R is the correct explanation of A
b. Both A and R are true but R is not the correct explanation of A.
c. A is true but R is false.
d. A is false but R is true.
SECTION-B
What happens when D-glucose is treated with. the following reagents? 2
19
(i)HI ) Bromine water
2
20 What are essentialand non-essential amino acids? Give one examples ofeach type
21 How are vitamins classified? Give example ofeach type? 2
OR
Name the diseasecaused due to deficiency of Vitamin Eand Ascorbicacid?
22 What are the hydrolysis products of (i) Maltose and (i)lactose 2
OR

What isZwitterion? Howis it formed?

23 What is glycogen? How is it differentfrom starch?
24 Write theimportanttwostructural differences between DNAand RNA?
25 Differentiate between a- helical and B-pleated sheet structure of secondary protein? 2

SECTION-C
26 Enumerate the reactions ofD-glucose which cannot be explained by its open chain structure? 3
27 (aWhat is the biological effect of denaturation of proteins? 3
(b) What are enzymes?
 28 Differentiate betweenfollowing
(i) Globular protein and Fibrous protein
(i) Nucleotide and Nucleoside
write the
29 do when D-glucose reacts with following reagent,
What information we get
reaction also
(ii) nitric acid
(a)Hydroxylamine (iilacetic anhydride

30 (a)What are reducing and non-reducing sugar? Give example of each?

(b}What are anomers?
OR
(a)Explain the formation of peptide linkage in protein?
(bjWhat arethe twotypesof proteinonthebasisof molecularshape?
SECTION-D
31 Read the text carefully and answer the questions:
When a protein in its native form, is subjected to physical changeslike change in
or chemical changes like change in pH, the hydrogen bonds are disturbed. Due to this, globules
temperature
unfold and helix gets uncoiled and protein loses its biological activity. This is called the
denaturation of protein. The denaturation causes change in secondary and tertiary structures
but primary structures remain intact. Examples of denaturation of protein are coagulation of
egg white on boiling, curdling of milk, formation of cheese when an acid is added to milk.

(a) Phospholipids form a thin layer on the surface of an aqueous medium. Give reason.
(b) Which structure of proteins remains intact during the denaturation process?
(c) What type of structure is a -helix and B-pleated structures of proteins?
OR
Why do amino acids have high molar masses comparable to ionic solids?
32
Read the text carefully and answer the questions:
The activity of an enzyme can be affected by a change in the conditions which can alter the
|
tertiary structure of the protein. These include temperature, pH, and change in substrate
concentration or binding of specific chemicals that regulate its activity. Enzymes generally
function in a narrow range of temperature and pH. Each enzyme shows its highest activity at a
particular temperature and pH called the optimum temperature and optimum pH. Activity
declines both below and above the optimum value. Low temperature preserves the enzyme in
a temporarily inactive state whereas high temperature destroys enzymatic activity because
proteins are denatured by heat. Concentration of Substrate With the increase in substrate
concentration, the velocity of the enzymatic reaction rises at first. The reaction ultimately
reaches a maximum velocity (Vmax) Which is not exceeded by any further rise in concentration
of the substrate. This is because the enzyme molecules are fewer than the substrate molecules
and after saturation ofthese molecules, there are no free enzyme molecules to bind with the
additional substrate molecules.
(a) Name a chemical compound or molecule which is responsible for decrease or stop the
enzyme activity by binding to an enzyme?
(b) Give reason why most of the enzymes get destroyed above optimum temperature?
(c) Explain the relation between substrate concentration and enzymatic activity?
OR
What are co-enzyme and co-factor?
SECTION E
33 (a)Write the name and molecular formula of nitrogenous bases present in DNA and RNA?
(b) What are different types of RNA found in the cell?
 Ic) write two important functions of nucleic
34 (a) Write functional difference between DNAacid?and RNA?
(b) What is the basic structural difference
between starch and cellulose?
OR
(a) Which form of glucose is obtained
solution at 371K?
by crystallization from hot and saturated aqueous
(b) What is chemical formula of
(c) What are oligosaccharides? glyceraldehyde?
(d) The molecular formula of a
compound is Cz(H20}2» Is it a carbohydrate, explain your
answer?
35 (a) Name the various sugars present in RNA & DNA?
(6JExplain Cyclic structure of Fructose?
OR
(a )Explain the cyclic structure of Glucose?
b)How Nucleotides are joined together in DNA molecule

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