Anna University Enzyme Technology Model Test Paper

Anna University Enzyme Technology Model Test Paper

ENZYME ENGINEERING & TECHNOLOGY

 

Time : 3 Hours                                              Max.Marks: 100

PART A         (10 X 2 = 20 Marks)

Answer ALL Questions

  1. Give      an example of
  1. Enzymes used for the manufacture of fructose syrup from starch.
  2. A recombinant enzyme approved for use in the dairy products.
  1. Explain with an      example indirect assay of an enzymatic reaction.
  2. Write down 2 methods      of separation of proteins from low molecular weight solutes
  3. Sucrose + HO      —> glucose + fructose

The equilibrium constant for the conversion of the disaccharide sucrose to the simple sugars glucose and fructose is 140,000.

What can you conclude from the above?

(a)      Its a closed system

(b)     It never reaches equilibrium

(c)      It is spontaneous, starting with sucrose

(d)     At equilibrium, the concentration of sucrose is much higher than the concentration of glucose and fructose.

  1. What are Biosensors?      Give an example
  2. Explain Thiele      Modulus. Write down the expression for Thiele modulus for a first order      reaction, spherical geometry.
  3. List any 2 downstream      processing steps involved in the extraction of intracellular enzymes.
  4. When alcohol      dehydrogenase was immobilized on polyacrylamide, Km for Butanol      was 0.1 mM. When the enzyme was immobilized on a polymer of methacrylate      and acrylamide, Km for Butanol was found to be 0.025 mM.      Explain the above (Assume all other conditions to be identical for both      the cases)
  5. Define V (maximum      velocity), KmA       KmB for a two substrate reaction and explain      how one will evaluate the true kinetic parameters.
  6. Methanol      is a poison not because of what it does to the body itself but because the      enzyme alcohol dehydrogenase oxidizes it to formaldehyde, which is a      potent poison. A treatment of methanol poisoning is to give the patient      ethanol (CH3CH2OH). Why is this effective?

 

Part –B

                   (Question No. 11 is Compulsory)   (5 x 16 = 80 Marks)

  1. The kinetics of an enzyme were      analyzed in the absence and presence of inhibitors A and B.

(S)   (mM)

Vo   (Moles/minute)

No   inhibitor

5mM   A

0.1   mM B

1.0 43 30 26
2.0 68 50 41
5.0 105 86 64
10.0 128 113 77
20.0 144 134 88

 

a) What type of inhibitors are A and B: Competitive or

NonCompetitive? (Use your graphs to answer this question).

b) In addition to calculating Km and V­ (mazimum velocity) in the absence of

inhibitors, calculate the Ki constants for the inhibitors A and B.

 

12. Discuss the application of enzymes in the food and detergent industry

(OR)

Outline the method of manufacture of High Fructose corn syrup and explain the steps involved.

 

13. Derive an expression for the concentration profile of a substrate following first order kinetics and spherical geometry considering internal mass transfer.

(OR)

Explain the different methods of immobilization of enzymes, discussing the advantages and disadvantages.

 

14. Penicillin is hydrolyzed and thereby rendered inactive by penillicinase (also known as b-lactamase), an enzyme present in some resistant strains of bacteria. The molar mass of this enzyme is 29,000 g/mole. The amount of penicillin hydrolyzed in 1 minute in a 10 mL solution containing 10-9 g of purified enzyme was measured as function of the concentration of penicillin (in µmol/L). Assume the concentration of penicillin does not change appreciably during the assay.

[Penicillin}

Amount Hydrolyzed   (nmols)

1

0.11

3

0.25

5

0.34

10

0.45

30

0.58

50

0.61

 

a.)  Plot 1/rate vs. 1/[S] for these data.

b.)  What is KM?

c.)  What is Vmax?

d.)  What is the turnover number?

(OR)

a)  Rearrange the Michaelis – Menton equation to give Eadie-Hofstee        plot

b)  What is the significance of the i) slope ii) Vertical intercept iii) horizontal intercept?

c)  The reciprocal plot of a Bi-Bi reaction with ping pong mechanism for varying fixed substrate concentration generates parallel lines. Explain the above with the equation. Also provide a theoretical explanation.

 

15. a)  Define Damkholer Number, External effectiveness factor.

b)  Derive the relationship between External effectives factor he and

Damkholer number

(OR)

An enzyme is used to produce a compound used in manufacture of sunscreen lotion. Vmax for the enzyme is 2.5 mmol m?3 s-1; Km = 8.9 mM. The initial concentration of substrate is 12 mM.

(a)      Find the batch time required to achieve 90% substrate conversion.

(b)     Assume the enzyme deactivates with half-life of 4.4 hours. Calculate the batch time for 90% substrate conversion and compare it with the time required without deactivation.

 

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Time : 3 Hours                                              Max.Marks: 100

 

              PART A         (10 X 2 = 20 Marks)

Answer ALL Questions

1. Give      an example of

a. Enzymes used for the manufacture of fructose syrup from starch.

b. A recombinant enzyme approved for use in the dairy products.

2. Explain with an      example indirect assay of an enzymatic reaction.

3. Write down 2 methods      of separation of proteins from low molecular weight solutes

4. Sucrose + HO      —> glucose + fructose

The equilibrium constant for the conversion of the disaccharide sucrose to the simple sugars glucose and fructose is 140,000.

What can you conclude from the above?

(a)      Its a closed system

(b)     It never reaches equilibrium

(c)      It is spontaneous, starting with sucrose

(d)     At equilibrium, the concentration of sucrose is much higher than the concentration of glucose and fructose.

5. What are Biosensors?      Give an example

6. Explain Thiele      Modulus. Write down the expression for Thiele modulus for a first order      reaction, spherical geometry.

7. List any 2 downstream      processing steps involved in the extraction of intracellular enzymes.

8. When alcohol      dehydrogenase was immobilized on polyacrylamide, Km for Butanol      was 0.1 mM. When the enzyme was immobilized on a polymer of methacrylate      and acrylamide, Km for Butanol was found to be 0.025 mM.      Explain the above (Assume all other conditions to be identical for both      the cases)

9. Define V (maximum      velocity), KmA       KmB for a two substrate reaction and explain      how one will evaluate the true kinetic parameters.

10. Methanol      is a poison not because of what it does to the body itself but because the      enzyme alcohol dehydrogenase oxidizes it to formaldehyde, which is a      potent poison. A treatment of methanol poisoning is to give the patient      ethanol (CH3CH2OH). Why is this effective?

 

Part –B

                   (Question No. 11 is Compulsory)   (5 x 16 = 80 Marks)

11. The kinetics of an enzyme were      analyzed in the absence and presence of inhibitors A and B.

(S)   (mM)

Vo   (Moles/minute)

No   inhibitor

5mM   A

0.1   mM B

1.0 43 30 26
2.0 68 50 41
5.0 105 86 64
10.0 128 113 77
20.0 144 134 88

 

a) What type of inhibitors are A and B: Competitive or

NonCompetitive? (Use your graphs to answer this question).

b) In addition to calculating Km and V­ (mazimum velocity) in the absence of

inhibitors, calculate the Ki constants for the inhibitors A and B.

 

12. Discuss the application of enzymes in the food and detergent industry

(OR)

Outline the method of manufacture of High Fructose corn syrup and explain the steps involved.

 

13. Derive an expression for the concentration profile of a substrate following first order kinetics and spherical geometry considering internal mass transfer.

(OR)

Explain the different methods of immobilization of enzymes, discussing the advantages and disadvantages.

 

14. Penicillin is hydrolyzed and thereby rendered inactive by penillicinase (also known as b-lactamase), an enzyme present in some resistant strains of bacteria. The molar mass of this enzyme is 29,000 g/mole. The amount of penicillin hydrolyzed in 1 minute in a 10 mL solution containing 10-9 g of purified enzyme was measured as function of the concentration of penicillin (in µmol/L). Assume the concentration of penicillin does not change appreciably during the assay.

[Penicillin}

Amount Hydrolyzed   (nmols)

1

0.11

3

0.25

5

0.34

10

0.45

30

0.58

50

0.61

 

a.)  Plot 1/rate vs. 1/[S] for these data.

b.)  What is KM?

c.)  What is Vmax?

d.)  What is the turnover number?

(OR)

a)  Rearrange the Michaelis – Menton equation to give Eadie-Hofstee        plot

b)  What is the significance of the i) slope ii) Vertical intercept iii) horizontal intercept?

c)  The reciprocal plot of a Bi-Bi reaction with ping pong mechanism for varying fixed substrate concentration generates parallel lines. Explain the above with the equation. Also provide a theoretical explanation.

 

15. a)  Define Damkholer Number, External effectiveness factor.

b)  Derive the relationship between External effectives factor he and

Damkholer number

(OR)

An enzyme is used to produce a compound used in manufacture of sunscreen lotion. Vmax for the enzyme is 2.5 mmol m?3 s-1; Km = 8.9 mM. The initial concentration of substrate is 12 mM.

(a)      Find the batch time required to achieve 90% substrate conversion.

(b)     Assume the enzyme deactivates with half-life of 4.4 hours. Calculate the batch time for 90% substrate conversion and compare it with the time required without deactivation.

 

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