Questions and answers for exam Preparation

MCQs

Total Questions : 54 | Page 3 of 6 pages

Question 21. For glucose isomerization by immobilized enzyme, the reactor generally used is

CSTR
plug flow
packed bed
fluidized bed

Discuss Question

Answer: Option C. -> packed bed
Answer: (c).packed bed

Question 22. If Damkohler number, NDa >>1, the reaction rate is much greater than the mass transfer rate and the overall reaction is controlled by the rate of mass transfer. In this case, the enzyme reaction can be described as (where Csb and Cs are the substrate concentration in bulk of solution and at the immobilized enzyme surface respectively. ks mass transfer coefficient, and a is the surface area of an immobilized enzyme particles)

rp = ksa(Csb-Cs)
rp = ksaCsb
rp = ksaCs
rp = ksa(Csb+Cs)

Discuss Question

Answer: Option B. -> rp = ksaCsb
Answer: (b).rp = ksaCsb

Question 23. Which of the following is not the correct answer?

Immobilized enzyme may show selectively altered chemical properties
Immobilized enzyme may show selectively altered physical properties
Immobilized enzyme may simulate the realistic natural environment where the enzyme come from the cell
None of the above

Discuss Question

Answer: Option D. -> None of the above
Answer: (d).None of the above

Question 24. The most commonly employed cross-linked polymer is the

polyacrylamide gel
collagen
celluloses
cation exchange resin

Discuss Question

Answer: Option A. -> polyacrylamide gel
Answer: (a).polyacrylamide gel

Question 25. Commonly employed water insoluble supports for the covalent attachment of enzyme include

acrylamide based polymers
polypeptides
dextran
all of these

Discuss Question

Answer: Option D. -> all of these
Answer: (d).all of these

Question 26. Functional groups of the nonessential amino acid residues that are suitable for the immobilization process are

free α-, β- or γ carb oxyl groups
α or β amino groups
phenyl, hydroxyl, sulfhydryl or imidazole groups
all of the above

Discuss Question

Answer: Option D. -> all of the above

Question 27. Water insoluble enzymes can be prepared by using multifunctional agents that are bifunctional in nature and have

low molecular weight
high molecular weight
high equivalent weight
low reactivity

Discuss Question

Answer: Option A. -> low molecular weight

Question 28. The immobilized enzyme produced by micro encapsulation technique provides

an extremely large surface area
smaller surface area
high amount of solvent
relatively smaller surface area

Discuss Question

Answer: Option A. -> an extremely large surface area

Question 29.
Which of the following is taken as an assumption in the distributed model?

The reaction occurs at every position and the kinetics of the reaction are of the same form as observed for free enzyme.
Mass transfer through the immobilized enzyme occurs via molecular diffusion
There is no mass transfer limitation at the outside surface of the spherical immobilized enzyme
All of the above

Discuss Question

Answer: Option D. -> All of the above

Question 30. Which of the following is considered as a disadvantage to the adsorption method of immobilization?

It is possible to separate and purify the enzymes while being immobilized
The enzymes are not usually deactivated by adsorption
The adsorption is a reversible process
State of immobilization is very sensitive to solution pH, ionic strength and temperature

Discuss Question

Answer: Option D. -> State of immobilization is very sensitive to solution pH, ionic strength and temperature