NCERT CLASS 11 | TOPIC : BIOMOLECULES | QB-2 | NEET BIOLOGY ONLINE TEST

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NCERT CLASS 11 | TOPIC : BIOMOLECULES | QB-2 | NEET BIOLOGY ONLINE TEST

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It contains 86 important questions. Choose the most correct answer. Then check your answer. Try again if there are errors. Regards : www.onlinetest.kalvisolai.com

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1 ➤ 101. CO2 + H2O ⇐ H2CO3 Carbonic acid

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Which one of the following statement is incorrect about the above reaction?

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(a) In the absence of enzyme, the rate of H2CO3 formation is about 200 molecules per hour. (b) When carbonic anhydrase catalyses the same reaction, there is no change in the rate of H2CO3 formation. (c) The reaction catalyzed by the enzyme shows dramatically higher decrease speed about 600,000 molecules being formed every second (rate becomes 10 million times more). (d) The enzymes carbonic anhydrase occurs in abundance of RBC's.

2 ➤ 102. Fill in the blanks in the below statements: A. A multistep chemical reaction, when each of the steps is catalyzed by the same enzyme complex or different enzymes is called a _________ 1 _________ pathway. B. In our skeletal muscle, under anaerobic conditions, _________ 2 _________ is formed. C. In yeast, during fermentation, the gylcolytic pathway leads to the production of _________ 3 _________.

(a) 1-metabolic pathway 2-acetic acid 3-ethanol (b) 1-glycolytic pathway 2-lactic acid 3-ethanol (c) 1-glycolytic pathway 2-ethanol 3-ethanol (d) 1-metabolic pathway 2-lactic acid 3-ethanol

3 ➤ 103. There could be many more altered structural states (like transition state) between the stable substrate and the product in enzymatic reaction. These structural states are

(a) Stable (b) Unstable (c) Metastable (d) Of lower energy than both substrate and product

4 ➤ 104. Which one of the following statements about enzymes is true?

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1. Enzymes are proteins whose three dimensional shape is key to their functions.

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2. Enzymes speed up reactions by lowering the activation energy.

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3. Enzymes are highly specific for reactions.

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4. Enzyme activity is affected by the change in temperature and pH.

(a) All except 2 (b) All except 1 (c) All except 3 (d) All of these

5 ➤ 105. Which of the following is a unique feature about the enzyme?

(a) They are not consumed by the enzyme-mediated reaction. (b) They are not altered by the enzyme-mediated reaction. (c) They lower the activation energy. (d) All of these

6 ➤ 106. The catalytic cycle of an enzyme action can be described in the following steps. Arrange them in sequence accordingly.

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1. The binding of the substrate induces the enzyme to alter its shape, fitting more tightly around the substrate.

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2. The substrate binds to the active site of the enzyme, fitting into the active site.

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3. The enzyme releases the products of the reaction and the free enzyme is ready to bind to another molecule of the substrate and run through the catalytic cycle once again.

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4. The active site of the enzyme, now in close proximity of the substrate breaks the chemical bonds of the substrate and the new enzyme product complex is formed.

(a) 1 → 2 → 3 → 4 (b) 2 → 1 → 4 → 3 (c) 1 → 2 → 4 → 3 (d) 2 → 1 → 3 → 4

7 ➤ 107. The activation energy for given reaction is (i.e., reactant → product):

(a) Energy of transition state - Energy of substrate (b) Energy of transition state - Energy of product (c) Threshold energy - Energy of transition state (d) All are correct

8 ➤ 108. Which one is correct?

(a) E + S → ES → EP → EP (b) E + S → ES → EP → E + P (c) E + S → ES → EP → E – P (d) E + S → ES → EP → E – P

9 ➤ 109. Which one of the graphs shows the effect of pH on the enzymatic activity (EA)?

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A) B) C) D)

10 ➤ 110. Which one of the graphs shows the effect of temperature on the enzymatic activity?

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A) B) C) D)

11 ➤ 111. Which one of the following graphs show the relationship between the of an (EA) and substrate conc.(S)?

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A) B) C) D)

12 ➤ 112. Each enzyme shows its highest activity at particular temperature and pH called the __1____ temperature and ___2___ pH.

(a) optimum, optimum (b) minimum, minimum (c) maximum, maximum (d) minimum, maximum

13 ➤ 113. Select the correct statement:

(a) Low temperature preserves the enzyme in a temporarily inactive state. (b) Higher temperature destroys enzymatic activity because proteins are denatured by heat. (c) The activity of enzymes declines both below and above the optimum value. (d) All of these

14 ➤ 114. Select the correct statement:

(a) Increase in substrate concentration, increases the velocity of enzymatic reaction at first then it reaches maximum and further increment does not occur. (b) In competitive inhibition, the inhibitor closely resembles the substrate in its molecular structure. (c) Competitive inhibition are often used in the control of bacterial pathogens. (d) All of these

15 ➤ 115. The activity of an enzyme is also sensitive to the presence of specific chemicals that bind to the enzyme. When the binding of the chemical shuts off enzyme activity, the process is called _________ and the chemical is called an _________ .

(a) activation, activator (b) inhibition, inhibitor (c) Inhibition, promoter (d) activation, inhibitor

16 ➤ 116. Inhibition of succinate dehydrogenase by malonate is an example of

(a) Non-competitive inhibition (b) Negative feed back (c) Allosteric inhibition (d) Competitive inhibition

17 ➤ 117. Enzymes are divided into

(a) 6 classes, each with 4.13 subclasses and named accordingly by a four-digit number. (b) 7 classes, each with 3.13 subclasses and named accordingly by a four-digit number. (c) 7 classes, each with 4.13 subclasses and named accordingly by a three-digit number. (d) 6 classes, each with 4.20 subclasses and named accordingly by a four-digit number.

18 ➤ 118. Enzymes which catalyse oxidoreduction between two substrate belongs to the class

(a) Oxidoreductase (b) Transferase (c) Hydrolase (d) Ligase

19 ➤ 119. Enzymes which catalyse transfer of group other than hydrogen belongs to the class

(a) Oxidoreductase (b) Transferase (c) Hydrolase (d) Ligase

20 ➤ 120. Enzymes which catalyse hydrolysis of ester, ether, peptide, glycosidic bond belongs to the class

(a) Oxidoreductase (b) Transferase (c) Hydrolase (d) Ligase

21 ➤ 121. Enzymes that catalyse removal of groups from substrates by mechanisms other than hydrolysis leaving double bonds is known as

(a) Oxidoreductase (b) Transferase (c) Hydrolase (d) Lyase

22 ➤ 122. Enzymes which catalyse the inter-conversion of optical, geometric or positional isomers belongs to the class of class

(a) Isomerase (b) Transferase (c) Hydrolase (d) Ligase

23 ➤ 123. Enzymes catalysing the linking together of two compounds, for example enzymes which catalyse the joining of C-O, C-S, C-N, P-O, etc., bonds, belongs to the class of

(a) Isomerases (b) Transferases (c) Hydrolases (d) Ligases

24 ➤ 124. How many types of cofacter can be identified?

a) 1 (b) 2 (c) 3 (d) 4

25 ➤ 125. The suffix ‘–’ added to substrate for naming the enzyme is

(a) –ase (b) –in (c) –zyme (d) –ose

26 ➤ 26. Ptylin is an example of

(a) Oxidoreductase (b) Transferase (c) Hydrolase (d) Ligase

27 ➤ 127. When Apoenzyme is separated from its metal component, its activity is

(a) Decreased (b) Increased (c) Lost (d) Remains unaffected

28 ➤ 128. Cofactors are

(a) Prosthetic groups (b) Co-enzymes (c) Metallic ions (d) All of these

29 ➤ 129. Which of the following combinations is correct?

(a) Metal ions loosely attached with Apoenzyme.Activators. (b) Non-protein organic part attached tightly to the Apoenzyme.Prosthetic group. (c) Non-protein organic part attached loosely to the Apoenzyme.Coenzyme. (d) All of these

30 ➤ 130. Which one of the following is not a cofactor?

(a) Coenzyme (b) Metal ions (c) Prosthetic group (d) Apoenzyme

31 ➤ 131. Haem is a prosthetic group of _________ enzyme

(a) Peroxidase (b) Catalase (c) Both (a) and (b) (d) None of these

32 ➤ 132. Zn is an activator of _________ enzyme.

(a) Carbonic anhydrase (b) Carboxypeptidase (c) Carboxylases (d) All of these

33 ➤ 133. Which of the following statement is correct?

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(1) Catalytic activity is lost when the co-factor is removed from the enzyme.

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(2) Coenzyme nicotinamide adenine dinucleotide (NAD) and NADP contains the vitamin niacin.

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(3) Biomacromolecules have a hierarchy of structures such as primary, secondary, tertiary and quaternary.

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(4) Enzymes lower the activation energy of reactions and enhance greatly the rate of the reactions.

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(5) Nucleic acids carry hereditary information and are passed on from parental generation to progeny.

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(a) 1 and 5 only (b) 2 and 3 only (c) 2 and 5 only (d) All of these

34 ➤ 134. The figure given below shows the conversion of a substrate into product by an enzyme. In which one of the options (a to d) the components of reaction labelled as A, B, C and D are identified correctly?

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(a) [A] Potential energy [B] Transition state [C] Activation energy with enzyme [D] Activation energy without enzyme (b) [A] Transition state [B] Potential energy [C] Activation energy without enzyme [D] Activation energy with enzyme (c) [A] Potential energy [B] Transition state [C] Activation energy without enzyme [D] Activation energy with enzyme (d) [A] Activation energy with enzyme [B] Transition state [C] Activation energy without enzyme [D] Potential energy

35 ➤ 135. Assertion: Arachidonic acid is an unsaturated fatty acid.

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Reason: There are one or more double bonds which are present between the carbon atoms in unsaturated fatty acids.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

36 ➤ 136. Assertion: Amino acids are amphoteric in their function.

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Reason: All amino acids are necessary for our body.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

37 ➤ 137. Assertion: Coenzyme is a nonprotein group without which enzymes are inactive or incomplete.

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Reason: Coenzymes not only provide a point of attachment for the chemical group being transformed but also influence the properties of the group.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

38 ➤ 138. Assertion: Activity of an enzyme is pH dependent.

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Reason: Change in pH, affects the solubility of the enzyme in water.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

39 ➤ 139. Assertion: The coenzymes or metal ions that is very tightly bound to enzyme protein is called prosthetic group.

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Reason: A complete, catalytically active enzyme together with its bound prosthetic group is called apoenzyme.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

40 ➤ 140. Assertion: Enzymes are proteins which catalyse the biochemical reactions.

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Reason: The enzymes itself is unchanged in the reaction, its presence allows the reaction to take place.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

41 ➤ 141. Assertion: Simple carbohydrates having free aldose or ketose group are called reducing sugars.

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Reason: They can reduce cupric ion to cuprous state.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

42 ➤ 142. Assertion: Protein amino acids possess an amino group attached to a carbon (α amino acid).

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Reason: Proline and hydroxyproline have NH (imino group) so they are imino acids.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

43 ➤ 143. Assertion: Linolenic acid is the precursor of arachidonic acid.

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Reason: Ascorbic acid is a sugar acid having NH2 group.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

44 ➤ 144. Assertion: Protein is a heteropolymer.

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Reason: Protein is made up of amino acid.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

45 ➤ 145. Assertion: Watson.Crick model of DNA is the secondary structure of DNA.

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Reason: It contains covalent as well as hydrogen bond.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

46 ➤ 146. Assertion: The total number of amino acids involved in protein synthesis in plants is 20.

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Reason: Only 20 amino acids have been discovered so far.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

47 ➤ 147. Assertion: In human body ‘collagen’ is the most abundant protein.

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Reason: Scleroproteins occurs in hard parts of animals body for providing support and protection.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

48 ➤ 148. Assertion: Living state is a non.equilibrium steady state to be able to perform work.

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Reason: System at equilibrium cannot perform work.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

49 ➤ 149. Assertion: ATP is energy currency of cell.

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Reason: ATP is formed in catabolic pathway.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

50 ➤ 150. Assertion: There are two hydrogen bond exist between A&T.

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Reason: There are three hydrogen bond exist between G&C.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

51 ➤ 151. Assertion: The distance between adjacent base pair in B- DNA is 3.4 A°.

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Reason: One full turn of helical strand of B-DNA contain 10 bp and the length of this pitch is 34 A°.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

52 ➤ 152. Assertion: In proteins only left handed helix are observed exists in nature.

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Reason: Protein found only in secondary structure.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

53 ➤ 153. Assertion: Tertiary structure is necessary for the many biological activities of proteins.

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Reason: Tertiary structure in 3-dimentional view of protein.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

54 ➤ 154. Assertion: DNA is called deoxyribonucleic acid.

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Reason: DNA is nucleic acid containing deoxyribose sugar.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

55 ➤ 155. Assertion: RuBisCO is most abundant protein in the whole biosphere.

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Reason: RuBisCO is present in all animal cells.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

56 ➤ 156. Assertion: Starch forms complex with I2.

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Reason: Starch forms secondary helical structure.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

57 ➤ 157. Assertion: Cellulose is homo polymer.

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Reason: Cellulose formed of only one type of monosaccharide viz. glucose

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

58 ➤ 158. Assertion: Co-factor play sepical role in the catalytic activity of enzyme.

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Reason: Catalytic activity is lost when co-factor is removed.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

59 ➤ 159. Assertion: Living organism contain only biomolecules

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Reason: Biomolecules are made up of carbon atoms only

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

60 ➤ 160. Assertion: DNA and RNA consists of nucleotides only

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Reason: Nucleotides are monomer of Nucleic acid

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

61 ➤ 161. Assertion: Biomacromolecules are those which are found in acid soluble fraction

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Reason: Biomacromolecules gave molecular weight less than 1000 dalton.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

62 ➤ 162. Assertion: Starch with I2 gives blue colour because of starch I2 complex.

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Reason: Starch Can hold I2 in their helical portion

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

63 ➤ 163. Assertion: Cellulose doesn’t give colour with I2

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Reason: Cellulose doesn’t contain helix which can hold I2

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

64 ➤ 164. Assertion: In polysaccharide chain the right end is reducing

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Reason: The right end contain free anomeric -OH group.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

65 ➤ 165. Assertion: Chitin is homopolymer.

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Reason: Chitin is made up of only one type of monomer i.e. N-acetylglucosamine.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

66 ➤ 166. Assertion: The first amino acid in primary structure protein is called as N-terminal amino acid.

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Reason: NH2 group of first amino acid is free, not bound to form peptide bond.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

67 ➤ 167. Assertion: Oil containing PUFA are good for health.

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Reason: They reduce blood cholesterol level. Thus, decreases chance of heart diseases.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

68 ➤ 168. Assertion: A B-DNA structure proposed by Watson and Crick is secondary structure.

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Reason: B- DNA contains hydrogen bond in addition to covalent bond.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

69 ➤ 169. Assertion: Conversion of glucose to lactic acid in our skeletal muscle is catabolic pathways.

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Reason: In this metabolic pathway complex structure is degraded to simpler one.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

70 ➤ 170. Assertion: All enzymes are protein.

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Reason: RNA can’t act as enzyme .

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

71 ➤ 171. Assertion: Enzymes isolated from thermophilic organisms are thermally stable.

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Reason: They retain their catalytic power even at higher temperature.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

72 ➤ 172. Assertion: Enzyme increases the rate of biochemical reactions.

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Reason: Enzymes lower down the energy of activation. previous year questions

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion. (b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion. (c) If the assertion is true but the reason is false. (d) If both the assertion and reason are false.

73 ➤ 1. lt is said that the elemental composition of living organisms and that of inanimate objects (like earth’s crust) are similar in the sense that all the major elements are present in both. Then what would be the difference between these two groups? Choose a correct answer from among the following:

(a) Living organisms have more gold in them than inanimate objects. (b) Living organisms have more water in their body than inanimate objects. (c) Living organisms have more carbon, oxygen and hydrogen per unit mass than inanimate objects. (d) Living organisms have more calcium in them than inanimate objects.

74 ➤ 2. Many elements are found in living organisms either free or in the form of compounds. One of the following is not found in living organisms.

(a) Silicon (b) Magnesium (c) Iron (d) Sodium

75 ➤ 3. Amino acids, as the name suggests, have both an amino group and a carboxyl group in their structure. In addition, all naturally occurring amino acids (those which are found in proteins) are called L.amino acids. From this, can you guess from which compound can the simplest amino acid be made?

(a) Formic acid (b) Methane (c) Phenol (d) Glycine

76 ➤ 4. Many organic substances are negatively charged, for e.g., acetic acid, while others are positively charged for e.g., ammonium ion. An amino acid under certain conditions would have both positive and negative charges simultaneously in the same molecule. Such a form of amino acid is called

(a) Positively charged form (b) Negatively charged form (c) Neutral form (d) Zwitterionic form

77 ➤ 5. Sugars are technically called carbohydrates referring to the fact that their formulae are only multiple of C(H2O). Hexoses therefore have six carbons, twelve hydrogenfs and six oxygen atoms. Glucose is a hexose. Choose another hexose from among the following.

(a) Fructose (b) Erythrose (c) Ribulose (d) Ribose

78 ➤ 6. When you take cells or tissue pieces and grind them with an acid in a mortar and pestle, all the small biomolecules dissolves in the acid. Proteins, polysaccharides and nucleic acids are insoluble in mineral acid and get precipitated. The acid soluble compounds include amino acids, nucleosides, small sugars, etc. When one adds a phosphate group to a nucleoside one gets another acid soluble biomolecule called

(a) Nitrogen base (b) Adenine (c) Sugar phosphate (d) Nucleotide

79 ➤ 7. When we homogenize any tissue in an acid, the acid soluble pool represents

(a) Cytoplasm (b) Cell membrane (c) Nucleus (d) Mitochondria

80 ➤ 8. The most abundant chemical in living organisms could be

(a) Protein (b) Water (c) Sugar (d) Nucleic acid

81 ➤ 9. A homopolymer has only one type of building block called monomer repeated enf number of times. A heteropolymer has more than one type of monomers. Proteins are heteropolymers made of amino acids. While a nucleic acid like DNA or RNA is made of only 4 types of nucleotide monomers, proteins are made of

(a) 20 types of monomers (b) 40 types of monomers (c) 3 types of monomers (d) Only one type of monomer

82 ➤ 10. Proteins perform many physiological functions. For example, some functions as enzymes. One of the following represents an additional function that some proteins discharge

(a) Antibiotics (b) Pigments conferring colour to skin (c) Pigments making colours of flowers (d) Hormones

83 ➤ 11. Glycogen is a homopolymer made of

(a) Glucose units (b) Galactose units (c) Ribose units (d) Amino units

84 ➤ 12. The number of ‘ends’ in a glycogen molecule would be

(a) Equal to the number of branches plus one. (b) Equal to the number of branch points. (c) One (d) Two, one on the left side and another on the right side.

85 ➤ 13. The primary structure of a protein molecule has two ends.

(a) Two ends (b) One end (c) Three ends (d) No ends

86 ➤ 14. Enzymes are biocatalysts. They catalyse biochemical, reactions. In general they reduce the activation energy of reactions. Many physicochemical processes are enzyme mediated. Some examples of enzyme mediated reactions are given below. Tick the wrong entry.

(a) Dissolving CO2 in water (b) Unwinding the two strands of DNA (c) Hydrolysis of sucrose (d) Formation of peptide bond

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