Enzyme Technology Multiple Choice Questions on “Large Scale Use of Enzyme – Glucose Oxidase and Catalase in Food Industry”.
1. Which enzyme catalyzes the oxidation of b-glucose to glucono-1,5-lactone and releasing hydrogen peroxide?
A. Pectin lyase
B. Cellulases
C. Catalases
D. Glucose oxidases
Answer: D
Clarification: Glucose oxidases is an enzyme which catalyzes the oxidation of b-glucose to glucono-1, 5-lactone and releasing hydrogen peroxide. Catalases acts on hydrogen peroxide and converts it to water and molecular oxygen. Cellulases breakdowns cellulose to glucose and galactose. Pectin lyase cleaves the pectin without the necessity of pectin methyl esterase action.
2. What does the X represent in the following reaction?
2H2O2 (underset{x}{rightarrow}) 2H2O + O2
A. Proteases
B. Pullulanases
C. Catalases
D. Glucose oxidases
Answer: C
Clarification: In the above reaction, ‘X’ is catalases which is an enzyme that catalyzes hydrogen peroxide to water and molecular oxygen. Catalase is derived from fungal fermentation as in case of glucose oxidases which catalyzes the oxidation of b-glucose to glucono-1, 5-lactone and releasing hydrogen peroxide. Proteases are the enzymes which cleaves proteins to smaller peptides. Pullulanases cleaves only a-1, 6-links to give straight-chain maltodextrins.
3. Glucose oxidase is derived from __________
A. bacillus subtilis
B. malted barley
C. aspergillus Niger
D. bacillus acidopullulyticus
Answer: C
Clarification: Glucose oxidase is derived from Aspergillus Niger. Pullulanase is derived from Bacillus acidopullulyticus. β – amylase is derived from malted barley. Saccharifying α – amylase is derived from Bacillus Subtilis.
4. Which of the following is not an application of glucose oxidase and catalase?
A. Meat tenderization
B. Removal of glucose from egg-white
C. Removal of oxygen from the head-space above bottled and canned drinks
D. Reducing non-enzymic browning in wines and mayonnaises
Answer: A
Clarification: Papain is a proteolytic enzyme and is used in meat tenderization. Application of glucose oxidase and catalase are as follows:
• Removal of glucose from egg-white before drying for use in the baking industry.
• Removal of oxygen from the head-space above bottled and canned drinks.
• Reducing non-enzymic browning in wines and mayonnaises.
5. Glucose oxidases improve the storage capability of foodstuffs.
A. True
B. False
Answer: A
Clarification: Glucose oxidases catalyzes the oxidation of b-glucose to glucono-1, 5-lactone and releasing hydrogen peroxide. It finds its use in the removal of glucose or oxygen from foodstuffs in turn improving its storage capability. Hence the above statement is true.
6. _________________ is an enzyme which converts hydrogen peroxide to water and molecular oxygen.
A. Pectinesterase
B. Cellulase
C. Catalase
D. Pullulanase
Answer: C
Clarification: Catalase is derived from the fungal fermentation and is an enzyme that converts hydrogen peroxide to water and molecular oxygen. Cellulase is an enzyme that converts cellulose to glucose and galactose. Pullulanase cleaves only a-1, 6-links to give straight-chain maltodextrins. Pectinesterase is an enzyme which releases methanol from the pectyl methyl esters.