Enzyme Technology Multiple Choice Questions on “Future Prospects – Artificial Enzymes”.
1. Synthetic polymers or oligomers with enzyme-like activities possess two structural entities, a substrate-binding site and a catalytically effective site are referred to as ___________
A. co-factors
B. co-enzymes
C. biosensors
D. synzymes
Answer: D
Clarification: Synthetic polymers or oligomers with enzyme-like activities possess two structural entities, a substrate-binding site and a catalytically effective site are referred to as synzymes. A cofactor is a non-protein chemical compound or metallic ion that is required for an enzyme’s activity as a catalyst. Coenzymes are non-protein organic molecules that bind loosely to an enzyme. Most of them are vitamins or are derived from vitamins. Biosensors are analytical devices that converts a biological response into an electrical signal.
2. Which of the following is not true for synzymes?
A. They are referred to as artificial enzymes
B. They possess two structural entities which are a substrate binding site and a catalytically effective site
C. They do not obey the Miachelis-Menten kinetics
D. Producing catalytic site is difficult
Answer: C
Clarification: The statement which is not true for synzymes is “they do not obey Miachelis-Menten kinetics.” The statement which is true for synzymes are as follows:
• They are referred to as artificial enzymes.
• They possess two structural entities which are a substrate binding site and a catalytically effective site.
• In this case, producing the catalytic site is difficult.
• In this case, producing facility for substrate binding is relatively straightforward.
3. Derivative of myoglobin acts as an effective natural ascorbate oxidase.
A. True
B. False
Answer: A
Clarification: Myoglobin is used as an oxygen carrier in muscle. The derivative of myoglobin is achieved by attaching (Ru(NH3)5)3+ to three surface histidine residues. This helps in conversion from an oxygen carrier to an oxidase by oxidizing ascorbic acid while reducing molecular oxygen. Thus, this derivative acts as an effective natural ascorbate oxidase. Hence the above statement is true.
4. Which of the following do not show synzymic properties?
A. Papain
B. Myoglobin
C. Polyglutamic acid
D. Cyclodextrins
Answer: A
Clarification: Papain do not show synzymic properties. It is a protease enzyme that is used in meat tenderization. The following items show synzymic properties:
• Derivative of myoglobin acts as an effective natural ascorbate oxidase and is achieved by attaching (Ru(NH3)5)3+ to three surface histidine residues.
• Polyglutamic acts as an esterase in the same fashion as the acid proteases for the hydrolysis of 4-nitrophenyl acetate.
• Cyclodextrins synthesized from starch by the cyclomaltodextrin glucanotransferase from Bacillus macerans. Synzymic cyclodextrins are usually derivatized in order to introduce catalytically relevant groups.
5. Cyclodextrins are synthesized from starch using __________
A. yeast
B. cyclomaltodextrin glucan transferase
C. B. acidopullulyticus
D. B. Licheniformis
Answer: B
Clarification: Cyclodextrins are synthesized from starch using cyclomaltodextrin glucanotransferase. Yeast is used to produce invertase which is used is used fermentation of wine. B. acidopullulyticus is used to produce pullulanase which cleaves α-1,6-links to give straight-chain maltodextrins. B. Licheniformis is used to produce Termamyl which is an α-amylase.
6. β-cyclodextrins was not as active as natural transaminases.
A. True
B. False