250+ TOP MCQs on Immobilized Enzymes – Preparation of Acrylamide and Answers

Enzyme Technology Multiple Choice Questions on “Immobilized Enzymes – Preparation of Acrylamide”.

1. Copper acts as a good catalyst in production of acrylamide.
A. True
B. False
Answer: B
Clarification: Acrylamide is produced by adding water to acrylonitrile in presence of copper. In this process, the yield is poor and may also cause unwanted conversion to acrylic acid (CH₂=CHCOOH) at relatively high temperatures and the catalyst is difficult to regenerate. Hence the above statement is false.

2. What does ‘X’ represent in the following reaction?
Acrylonitrile + water (underset{Cu}{rightarrow}) X
A. L-aspartic acid
B. Ampicillin
C. Acrylamide
D. Penicillin
Answer: C
Clarification: In the above reaction, ‘X’ represents acrylamide. Acrylamide is produced by adding water to acrylonitrile in the presence of copper. Penicillin is produced from Benzylpenicillins and phenoxymethylpenicillins in presence of penicillin amidases. Ampicillin is produced by the use of penicillin -G-amidase immobilised by adsorption to DEAE -cellulose in a packed bed column. L-aspartic acid is produced from fumaric acid in presence aspartases.

3. Immobilized ____________ is used in the production of acrylamide.
A. aspartase
B. raffinase
C. nitrilase
D. penicillin amidases
Answer: C
Clarification: Immobilized nitrilase is used in the production of acrylamide. Immobilized aspartase is used in the production of L-aspartic acid from fumaric acid. Immobilized raffinase is used to breakdown raffinase to galactose. Penicillin amidases are used in the production of penicillins.

4. Nitrilase is obtained from __________
A. Rhodococcus
B. Mortierella vinacea
C. Escherichia coli
D. Yeast
Answer: A
Clarification: Nitrilase used to produce acrylamide is obtained from Rhodococcus. Penicillin amidases and invertase is obtained from Escherichia coli and yeast respectively. Mortierella vinacea is used to produce raffinase which helps in the breakdown of raffinose sugar.

5. Immobilized ___________ is prepared by entrapping the intact Rhodococcus cells in a cross-linked polyacrylamide/dimethylaminoethylmethacrylate gel.
A. Raffinase
B. Nitrilase
C. Penicillin amidases
D. Aminoacyclase
Answer: B
Clarification: Immobilized nitrilase is prepared by entrapping the intact Rhodococcus cells in a cross-linked polyacrylamide/dimethylaminoethylmethacrylate gel. Penicillin amidases may be obtained from immobilizing Escherichia coli on a cyanogen bromide-activated Sephadex G200 support. Immobilized raffinase is prepared by stirring Mortierella vinacea with the sugar beet juice in a batch stirred tank reactors. Aminoacyclase is immobilised by adsorption to anion exchange resins and has an operational half-life of about 65 days at 50˚C in PBRs with residence times of about 30 min.

6. Immobilized Rhodococcus is used at 10˚C and pH 8.0-8.5 in a semi-batchwise process with low acrylonitrile concentration to produce __________
A. L-aspartic acid
B. Ampicillin
C. Acrylamide
D. Aminoacids
Answer: C
Clarification: Immobilized Rhodococcus is used at 10˚C and pH 8.0-8.5 in a semi-batchwise process with low acrylonitrile concentration to produce acrylamide. L-aspartic acid is obtained from immobilized aspartase produced from Escherichia coli. Ampicillin is produced from penicillin in presence of immobilized penicillin amidases from Escherichia coli. Aminoacids are produced from immobilized aminocyclases from Aspergillus Oryzae.

7. What does ‘Y’ represent in the following reaction?
HCN + 2H²O (underset{Y}{rightarrow}) HCOO^– + NH₄⁺
A. Cyanidase
B. L-aspartic acid
C. Penicillin
D. Nitrilase
Answer: A
Clarification: In the above reaction, ‘Y’ represents cyanidase enzyme which helps in removal cyanide producing acid and ammonia. L-aspartic acid is product obtained from fumaric acid. Penicillin is an antibiotic obtained from penicillin amidases. Nitrilase is an enzyme used to produce acrylamide from acrylonitrile.

8. What does ‘Z’ represent in the following reaction?
HCN + H₂O (underset{Z}{rightarrow}) HCONH₂
A. Raffinase
B. Cyanide hydratase
C. Cyanidase
D. Lactase
Answer: B
Clarification: In the above reaction, ‘Z’ represents cyanide hydratase which degrades cyanides. Cyanidase also helps in removal in cyanides, but the products and byproducts obtained are different. Raffinase breaks down raffinose sugars to galactose. Lactase degrades lactose to glucose and galactose.

9. Which of the following does not require the use of cyanidase or cyanide hydratase?
A. Remove cyanide from industrial waste
B. Detoxification of feeds
C. Cheese making
D. Detoxification of foodstuffs
Answer: C
Clarification: Rennet or chymosin is used in the production of cheese. Cyanidase or cyanide hydratase is used in degradation of cyanide. These are used in removal cyanide from industry, detoxification of feeds and foodstuffs containing amygdalin.