This set of Biochemical Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Biological Basics – Enzymes”.
1. What is the SI unit of enzyme activity?
a) mol s
b) s mol-1
c) mol s-1
d) mol min
View Answer
Explanation: The SI unit of enzyme activity is mol s-1. It is also called Katal.
1 Katal=1 mol s-1
2. Linear equation for the enzymatic reaction for a single batch reactor is:-
\(\frac{C_{s0}-C_s}{ln(\frac{C_s}{C_{s0}})}\) = -KM+\(\frac{r_{max}t}{ln(\frac{C_{s0}}{C_s})}\)
a) True
b) False
View Answer
Explanation: The correct equation for the single batch bioreactor foe an enzymatic reaction is:-
\(\frac{C_{s0}-C_s}{ln(\frac{C_{s0}}{C_s})}\) = -KM+\(\frac{r_{max}t}{ln(\frac{C_{s0}}{C_s})}\)
3. Identify the below given plot.
a) Line weaver plot
b) Langmuir plot
c) Eadie Hoftsee plot
d) Michealis Menten plot
View Answer
Explanation: The slope of Eadie Hoftsee plot is –KM. As the rate of reaction decreases the substrate concentration also decreases.
4. Identify the enzyme balance equation of Competitive Inhibition.
a) [E0] = [E] + [ES] + [EI]
b) [E0] = [E] + [EI]
c) [E0] = [ES] + [EI]
d) [E0] = [ESI] + [ES] + [EI]
View Answer
Explanation: Competitive inhibition is:-
Hence, the enzyme balance is;
[E0] = [E] + [ES] + [EI]
5. Which of these is a Co-factor for the enzyme Urease?
a) Mo
b) Ni2+
c) Mg2+
d) Cu2+
View Answer
Explanation: The co-factor for the enzyme Urease is Ni2+. The other options are the cofactors of Dinitrogenase, Hexokinase and Cytochrome oxidase respectively.
Co-factor | Enzyme |
Mo | Dinitrogenase |
Ni2+ | Ureas |
Mg2+ | Hexokinase, Glucose-6-phosphate, Pyruvate kinase. |
Cu2+ | Cytochrome oxidase |
6. __________ combines with an enzyme to alter the catalytic activity.
a) Inhibitor
b) Effector
c) Co-enzyme
d) Haloenzyme
View Answer
Explanation: Inhibitor is a modulator or effector molecule which decreases the catalytic activity. The inorganic ions which bind to the enzyme to perform its particular task are called Co-factor.
Cofactor+Apoenzyme=Haloenzyme
7. What is the substrate concentration when V0=Vmax/2?
a) KM/2
b) 0
c) KM
d) S0
View Answer
Explanation:
V0=\(\frac{V_{max}*S}{K_M+S} \)
\(\frac{V_{max}}{2}=\frac{V_{max}*S}{K_M+S} \)
KM = S
8. Why are the enzymes immobilized?
(i)For reuse
(ii)For slow rate of reaction
(iii)For minimum substrate
(iv)For maximum yield
a) Statement (i) and (iv) are correct
b) Statement (i) and (ii) are correct
c) Statement (i) and (iii) are correct
d) Statement (ii) and (iii) are correct
View Answer
Explanation: Enzymes immobilized so that they can be reused. The production cost and wastage of enzymes can be reduced. Large amount of substrate can be converted at a high rate to produce a large amount of yield.
9. Linear equation of an enzymatic reaction in a CSTR is:-
CS=KM+\(\frac{r_{max}*C_S*τ}{C_{S0}-C_S} \)
a) True
b) False
View Answer
Explanation: CSTR is continuous stirred tank reactor. The mode of operation is continuous i.e. continuous feed and continuous product recovery. The equation for an enzymatic reaction in a CSTR is: –
CS=KM+\(\frac{r_{max}*C_S*τ}{C_{S0}-C_S} \)
10. Which enzyme is used in Detergent industry to remove the stains?
a) Protease
b) Laccase
c) Amylase
d) Lactase
View Answer
Explanation: The enzyme protease has a wide variety of application in different industries. Its main application is in the detergent industry to remove the protein stains. Lipase enzyme can be used to remove the lipid stains.
ENZYME | INDUSTRY | FUNCTION |
Protease | Detergent | Remove the protein stains |
Laccase | Textile | Bleaching |
Amylase | Fuel | Starch Liquefication |
Lactase | Food | Removal of lactose content from milk |
11. Which of these methods is not a continuous enzyme assay?
a) Spectrophotometric
b) Calorimetric
c) Chromatographic
d) Light scattering
View Answer
Explanation: Chromatographic assays measure product formation by separating the reaction mixture into its components. Whereas, the other measures study a particular feature of the mixture for assay, like color, heat and etc.
12. Which industry uses the enzyme Pullulanase?
a) Animal feed
b) Paper and Pulp
c) Textile
d) Fuel
View Answer
Explanation: Pullulanase is used in the fuel industry. Its purpose is saccharification.
13. What is Isopynic condition during the extraction and purification of proteins?
a) Separation occurs by difference in size
b) Separation occurs by difference in density
c) Separation occurs by difference in molecular weight
d) Separation occurs by difference in concentration
View Answer
Explanation: Isopynic condition occurs when centrifugation is done at high speed in the presence of a gradient created by cesium chloride. This method is used for separating particles which differ in density.
14. Which enzyme can be used to increase the digestion in animals?
a) Cellulase
b) Xylanase
c) Pectinase
d) Peroxidase
View Answer
Explanation: Xylanase is used in the animal feed industry in order to increase the digestion in the animals.
15. Which of these is an organic synthetic carrier for enzyme immobilization?
a) Dextran
b) Porous glass
c) Silica
d) Polyvinyl acetate
View Answer
Explanation: Dextran is an organic natural polymer. Porous glass and silica are inorganic carriers.
Sanfoundry Global Education & Learning Series – Biochemical Engineering
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