Monday, August 30, 2021

Focus Area 2021 | Questions and Answers | Plus One Zoology | Biomolecules

BIOMOLECULES


1.   Which among the following is a primary metabolite? (Score 1)


Alkaloids, Antibiotics, Amino acids, Flavonoids

Answer: Amino acids


2.   When substrate concentration increases, the velocity of enzymatic reaction increases at first. After attaining a maximum velocity, it cannot be exceeded by further addition of substrates. Why? (Score 2)

Answer:

Because enzyme molecules are fewer than the substrate molecules i.e. No free enzyme molecules to bind with additional substrate molecules.


3.   Match the following: (Score 3)

Classification of Enzymes

Reactions

A

B

Hydrolases

Oxidation-reduction reactions

Lyases

Linking together of molecules

Oxidoreductases

Transfer of a group

Isomerases

Interconversion of molecules

Ligases

Removal of groups

Transferases

Hydrolysis of bonds


Answer:

Classification of Enzymes

Reactions

Hydrolases

Hydrolysis of bonds

Lyases

Removal of groups

Oxidoreductases

Oxidation-reduction reactions

Isomerases

Interconversion of molecules

Ligases

Linking together of molecules

Transferases

Transfer of a group


4.   Observe the diagrams A and B is given below:



    a.  What are ‘A’ and ‘B’?
    b.  Mention the other two levels of protein structure. (Score 2)

Answer:

(a) A= Secondary structure of protein, B= Tertiary structure of protein.

(b) Primary structure and quaternary structure.


5.   Proteins carry many functions in living organism. List any four. (Score 2)

Answer:

o For growth and tissue repair.

o Transport nutrients across cell membranes.

o Acts as intercellular ground substance.

o Acts as antibodies.


6.   Give one word. (Score 2)

a.   The organic compound tightly bound to the apoenzyme.

b.   The non-protein organic compound that are tightly bound to the apoenzyme.

c.   The protein part of the enzyme.


Answer:

        (i) Prosthetic group

        (ii) Cofactor

        (iii) Apoenzyme


7. a) List out any two factors affecting enzyme activity.
    b) Based on the reaction formulae given below, identify the classes of the enzymes.

i) S reduced + S’ oxidised → S oxidised + S’ reduced
ii) X - C – C - Y → X – Y + C = C     (Score 2)

Answer:

a) Temperature, pH, concentration of substrate etc.

b) (i) Oxidoreductases (Dehydrogenases).

      (ii) Lyases.

8. a) Effect of change in concentration of substrate on enzyme activity is graphically represented. After reaching a maximum velocity (Vmax), the reaction is not exceeded by any further rise in the concentration of substrate. Explain.

    b) Mention any 2 other factors that affect enzyme activity? (Score 3)



Answer:

a)    Because enzyme molecules are fewer than the substrate molecules i.e. No free enzyme molecules to bind with additional substrate molecules.

b)   Temperature and pH.


9. Fill in the blanks suitably. (Score 2)

a.    In a proteins amino acids are linked by ….…

b.    In a polysaccharide, individual monosaccharides are linked by…….…..

Answer:

(a) Peptide bond.

(b) Glycosidic bond.


10. Select the wrongly matched pair from the following: (Score 1)

Collagen

Intercellular ground substance

Insulin

Hormone

Antibody

Sensory reception

Trypsin

Enzyme


Answer:

Antibody: Sensory reception.


11.  Metabolites are organic compounds constantly utilized in various metabolic activities in the cells. (Score 2)

a)  What are the two types of metabolites in cells?

b)  Give an example for each type of metabolites.

Answer:


(a) Primary metabolites & Secondary metabolites.

(b) Primary metabolites: E.g. Glucose.

   Secondary metabolites: E.g. Terpenoids.


12.  Analyse the graph showing the activity of an enzyme, influenced by temperature.


a.  What is meant by optimum temperature?

b.  Why does the enzyme activity decline at too low and too high temperature? (Score 2)

Answer:

(a)  It is the temperature at which enzyme action is maximum.

(b)  At low temperature, enzyme is temporarily inactive.

At high temperature, enzymes destroy because proteins are denatured by heat.


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