BIOCHEMISTRY

C. the government will not approve the licensing of

pharmaceuticals produced in continuous cultures
BIOCHEMISTRY D. all of the above

1. Which of the following statements is not true? 9. Production of organic acids in batch culture is generally a
A. Enzymes are proteins that bind to specific substrates growth associated phase followed by non-growth
and increase the velocity of reactions involving those associated production. The probable reason for this is
substrates that
B. Enzymes function by overcoming the activation A. organic acids uncouple catabolism from
energy barrier of a reaction anabolism
C. Enzymes make thermodynamically favorable B. biomass yields increase as the fermentation
reactions to proceed; they cannot make unfavorable proceeds
reactions to occur C. organic acids are secondary metabolites
D. Enzymes only function when they are in intact D. high concentrations of organic acid promote the
cells growth of the microbial population

2. An enzyme and a reactant molecule maintain relationship 10. Biomass concentrations during fermentation is
as A. diluting the samples to optical density less than 0.3
A. a temporary association B. monitored by controlling the changes in biomass
B. an association stabilized by a covalent bond concentrations
C. one in which the enzyme is changed permanently C. considering that optical density is proportional to the
D. non complementary binding surface area of the biomass in the sample
D. all of the above
3. The active site of an enzyme remains
A. at the center of globular proteins 11. Turbine impeller consists of flat impeller blades with
B. rigid and does not change shape A. a vertical pitch welded directly to the shaft
C. complementary to the rest of the molecule B. a angled pitch welded directly to the shaft
D. none of the above C. a vertical pitch welded to
D. a horizontal disk a angled pitch welded to a
4. A classical uncompetitive inhibitor is a compound that horizontal disk
binds
A. reversibly to the enzyme substrate complex 12. At 25°C, the saturation concentration of oxygen in water
yielding an inactive ESI complex is 1.26 mmol/l and the partial pressure of oxygen is 1 atm.
B. irreversibly to the enzyme substrate complex The Henry's law constant will be
yielding an inactive ESI complex A. 0.793 atml/mmol C. 1.26 atml/mmol
C. reversibly to the enzyme substrate complex yielding B. 0.207 atml/mmol D. 8.74 atml/mmol
an active ESI complex
D. irreversibly to the enzyme substrate complex 13. Small propellers turn at the speed of either
yielding an active ESI complex A. 20 or 150 rpm C. 400 or 800 rpm
B. 150 or 300 rpm D. 1150 rpm or 1750
5. The types of inhibition pattern based on Michaelis rpm
Menten equation are
A. competitive C. uncompetitive 14. Which of the following models holds correct for the two-
B. non-competitive D. all of the above film theory? (where KL is the mass transfer coefficient,
DAB diffusivity and Zf film thickness)
6. Milk digestibility is improved by using A. KL = DAB/Zf C. KL= Zf/DAB
A. RNase C. β-amylase B. KL = DAB D. KL = DAB*Zf
B. lactase D. none of these
15. Pluronic F68 is added to cell culture media as
7. Which of the following metallic ion is there in ascorbic A. a nutrient
acid oxidase? B. a shear protectant
A. Mg C. Cu C. to increase oxygen transfer rates
B. Fe D. Mn D. all of these

8. The continuous cultures are not widely used in industry 16. Which of the following can act as a shear protectant?
because A. Serum C. Glucose
A. they are not suited for the production of secondary B. Silicone oil D. Glutamic acid
metabolites
B. contamination or mutation can have a disastrous 17. For the extractions operation, the selectivity should be
effect on the operation A. > 1 C. 1
B. < 1 D. zero
 BIOCHEMISTRY

A. 0 g.l-1 C. 1.0 g.l-1

18. Permanent hardness of water may be removed by the B. 0.5 g.l-1 D. 10 g.l-1
addition of
A. lime C. potassium permagnate 27. Continuous culture has an advantage over to a batch
B. soda ash D. sodium bicarbonate cultures as
A. continuous reactors do not need to be shut down and
19. Zeolite softening process removes both temporary and cleaned as regularly as a batch reactor
permanent hardness of water. In this process the calcium B. most downstream and upstream processes are
and magnesium present in water are precipitated as continuous in nature and thus the operation of
A. insoluble carbonates C. insoluble continuous bioreactor can be better integrated into
chlorides the overall manufacturing process
B. insoluble zeolites D. insoluble C. cells can be maintained at a constant physiological
sulfates state simply by setting the dilution rate
D. all of the above
20. The maximum desirable limit (BIS) of total hardness (as
CaCo3) in drinking water is 28. Which of the following is an example of a mathematical
A. 600 ppm C. 500 ppm model?
B. 300 ppm D. 1000 ppm A. Volume of cuboid = length x breadth x height
B. The Monod Model
21. Which graphical method is used to determine an enzyme C. The Michaelis Menten Equation
degree of cooperativity? D. All of the above
A. Hill plot
B. Koshland curve 29. A mixed fermentation is one, which produces
C. Michaelis-Menten hyperbola A. both alcohol and carbon dioxide
D. Can not be determined B. both acid and carbon dioxide
C. both acid and alcohol
22. The effect of non-competitive inhibition on a Lineweaver- D. several different kinds of acid
Burk Plot is that
A. it can move the entire curve to the right 30. Radial flow impellers
B. it can change the y-intercept A. provide high shear conditions for breaking up
C. it can change the x-intercept bubbles
D. all of these B. direct flow towards the walls of the reactor
C. Both (a) and (b)
23. Which is not the method for producing immobilized D. provide low shear conditions and are suited for use
enzymes with multifunctional reagents? in shear sensitive procesess
A. Enzymes are adsorbed on the surface active support
followed by intermolecular cross linking 31. Which of the following is not classified as an axial flow
B. Functional groups are introduced on the support to impeller?
react co-valently with enzymes A. A propeller C. A Rushton turbine
C. Enzymes are cross linked intermolecularly B. A marine impeller D. A hydrofoil impeller
D. None of the above
32. The maximum solubility of the alkane in the medium is 5
24. Commonly employed water insoluble supports for the ppm. If the actual dissolved concentration of the alkane
covalent attachment of enzyme include in the medium is 1 ppm. what conclusion may be drawn?
A. acrylamide based polymers A. The growth rate is limited by the rate of mass transfer
B. polypeptides of the alkane into the fermentation medium
C. dextran B. The growth rate is limited by the intrinsic kinetic
D. all of these properties of the cells and not by mass transfer
C. The growth rate is neither mass transfer nor
25. Discoloration can be achieved by using s kinetically limited
A. ulphloydryl oxidase D. No conclusion on the growth rate can be
B. proteases withdrawn
C. anthocyanase
D. all of these 33. Pure oxygen, if used instead of air will increase oxygen
transfer rates because
26. The growth of an organism on glucose is described by A. the saturation concentration of oxygen is higher
the following Monod model parameters: μm = 0.5 h-1 and B. the bubble size is smaller
Ks = 0.1 g.l-1, if the concentration of glucose in the feed C. the oxygen transfer coefficient is larger
is 10 g.l-1 and the dilution rate is set to 0.4 h-1, then the D. the partial pressure of oxygen in the gas phase is
steady state concentration of glucose in the effluent will lower
be
 BIOCHEMISTRY

34. Which of the following impellers generate a flow parallel 44. A continuous reactor has a dilution rate of 0.5 h-1. Its
to the axis of shaft? residence time would be
A. Axial flow C. Both (a)and(b) A. ln(2)/0.5 C. 0.5 h
B. Radial flow D. None of these B. ln(2) x 0.5 D. 2 h

35. Bioreactors, where vortex is formed, another 45. Which of the following would be correct concerning the
dimensionless number, __________ is useful. concentration of biomass (X). growth limiting substrate
A. Stanton C. Bond (S) and product (P) in a chemostat when the cells have
B. Rayleigh D. Froude been washed out?
A. X,S and P will be zero
36. A viscoelastic fluid is one in which the viscosity B. X,S and P can not be predicted for the above
A. is constant regardless of the stirrer speed or mixing condition
time C. X and P will be zero while S is equal to the
B. changes during mixing but returns to its original substrate concentration in feed
state after mixing D. None of the above
C. increases with increasing stirrer speed
D. decreases with increasing stirrer speed 46. In the stationary phase
A. growth is proportional to death
37. The radius of the filter with a depth of 14 cm required for B. growth rate is equal to death rate
a volumetric airflow rate of 10 m3/min is approximately C. growth rate is lesser than death rate
A. 1.6 m C. 3 D. no co-relation exist between death rate and growth
B. 0.6 m D. 6 m rate

38. Maintenance cost varies from 47. The relatively large volume (10 to 40% of total fermenter
A. 0-4% of the capital cost volume) of the seed culture is employed to
B. 12-16% of the capital cost A. increase the overall fermentation time
C. 4-8% of the capital cost B. increase the overall yield of biomass
D. 8-12% of the capital cost C. decrease the overall fermentation time
D. decrease the overall yield of product
39. Start up expenses in a fermentation industry varies from
A. 0-5% of the capital cost 48. The air riser is located on the outside of the draft tube for
B. 10-15% of the capital cost the large-scale airlift bioreactors because of
C. 5-10% of the capital cost A. higher oxygen transfer rates
D. 15-20% of the capital cost B. a small sparge ring
C. better heat transfer efficiencies
40. activated sludge process is sometime referred as D. all of these
A. fluid bed biological oxidation system
B. fixed bed biological oxidation system 49. The contents in bubble column and air lift reactor are
C. turning bed biological oxidation system mixed through
D. none of the above A. compressed air
B. a mechanical internal moving part
41. Enzymes are basically C. external pumping
A. proteins C. fat D. any of these
B. vitamins D. carbohydrates
50. Tower fermentors are used for
42. The immobilization technique involving physical method A. continuous penicillin production
is B. continuous beer production
A. covalent bond formation C. production of enzymes
B. dependent non-covalent bond formation D. batch production of beer
dependent
C. both (a) and (b) 51. If liquid density and viscosity remains constant, then the
D. ionic bond formation dependent Reynolds number in a stirred tank reactor will vary with
the
43. During the enzymatic reaction of an immobilized enzyme, A. impeller diameter
the rate of substrate transfer is B. square root of the impeller diameter
A. equal to that of substrate consumption C. square of the impeller diameter
B. more than that of substrate consumption D. cube of the impeller diameter
C. lesser than that of substrate consumption
D. is nothing to do with the substrate consumption 52. During fermentation, the saturation concentration of
oxygen was reduced from 7 ppm. to 1 ppm. Which one of
the following conclusions can be drawn?
 BIOCHEMISTRY

A. Microbial growth is oxygen limited since the oxygen 60. Application of quaternary ammonium compounds as
concentration is lesser than the saturation sanitizing agents tends to
concentration A. favor gram positive bacteria
B. Microbial growth is not oxygen limited since the B. decrease gram positive bacteria
oxygen concentration is lesser than the saturation C. increase the percentage of gram(-)ve rods on
concentration utensils
C. Experimental error leads to the reduction D. none of the above
D. No conclusion can be drawn
61. Which of the following activity is possible by
53. The best described action of Pluronic F68 (non-ionic transferases?
detergent) in a cell culture medium is that, it A. Transfer of methyl groups
A. acts on the surface properties of the cells and the B. Transfer of glycosyl group
culture medium C. Both (a) and (b)
B. provides nutrients for the cells D. None of these
C. acts as a flocculant
D. acts as a coagulant 62. The active site of an enzyme differs from an antibody-
antigen binding site in that the enzyme active site
54. The SI unit for viscosity is A. contains modified amino acids
A. kg*m-1*s-1 C. kg*m-3*s-1 B. catalyzes a chemical reaction
B. kg*m-2*s-2 D. kg*m-1*s-2 C. is complementary to a specific ligand
D. contains amino acids without side chains
55. The viscosity of water at STP is approximately
A. 0.005 kg*m-1*s-1 C. 0.003 kg*m-2*s-1 63. The equation for the rate of product formation for simple
-1 -1
B. 0.001 kg*m *s D. 0.1 g*cm-1*s-1 enzyme reaction is given by (Where rmax, maximum
reaction rate, Cs substrate concentration, Cp product
56. The viscosity of the culture fluid is classified as both concentration ES, CES enzyme-substrate concentration)
pseudoplastic and thixotropic which indicates that the A. rp = rmax Cs/(Km + Cs)
viscosity B. rp = rmax CES/(Km+ CES)
A. increases with stirring speed but decreases with C. rp = rmax Cs/(Km + CES)
mixing time D. rp = rmax Cs/(Km + Cp)
B. increases with stirring speed and increases with
mixing time 64. The slope of Lineweaver Burk plot for Michaelis Menten
C. decreases with stirring speed but increases with equation is
mixing time A. Vmax/Km C. 1/Km
D. decreases with stirring speed and decreases B. Km/Vmax D. Km.Vmax
with mixing time
65. Which is true about rennet?
57. The mechanism of air filtration in fibrous filter is A. It is a mixture of protease chymosin and pepsin
A. electrostatic attraction B. It is a mixture of rennin and pepsin
B. impaction C. Both (a) and (b)
C. interception D. none of the above
D. all of these
66. The enzyme used to reduce bitterness of grapes
58. The correlation often employed to correlate adsorption commonly contains
data for protein is (where Ymax is the maximum amount of A. α-L-rhamonosidase C. β- galactosidase
solute adsorbed per mass of adsorbent, X is the mass B. β-d-glucosidase D. both (a) and (b)
fraction of solute in the diluent phase in solute-free basis,
KL is a constant and Y is the equilibrium value of the mass 67. A culture system with constant environmental conditions
of solute adsorbed per mass of adsorbent) maintained through continual provision of nutrient and
A. Y = YmaxX/(KL+X) C. Y = YmaxX/KL removal of wastes is called __________ culture system.
B. Y= Ymax/(KL+X) D. Y = Ymax- X/(KL+X) A. continuous C. fed-batch
B. batch D. semi continuous
59. Zeolite used in zeolite softening process for the treatment
of hard water gets exhausted after certain time of usage 68. When two populations compete for a single growth
but can be regenerated by flushing it with limiting substrate in a continuous fermenter, which
A. 10% calcium chloride solution organism would not be washed out?
B. 10% magnesium sulfate solution A. Organism maintaining the highest substrate
C. 10% magnesium chloride solution concentration
D. 10% sodium chloride solution B. Organism maintaining the lowest substrate
concentration
C. Both (a) and (b)
 BIOCHEMISTRY

D. Organism maintaining the moderate substrate A. increasing particle diameter

concentration B. increasing air flow velocity
C. both (a) and (b)
69. Low dissolved oxygen concentrations leads to D. increasing particle size
A. low biomass yields
B. high biomass yields 79. The optimum wet solid content for the cell suspension for
C. no effect on biomass yields a bead mill is typically somewhere between
D. none of the above A. 5-15% by volume C. 30-60% by volume
B. 15-30% by volume D. 60-90% by volume
70. The specific growth rate (μ) is defined as
A. the concentration of biomass in the reactor 80. Sedimentation is a physical process used in wastewater
B. rate of increase of total biomass in a reactor treatment to
C. the rate of individual cells division or increase in A. remove particles that are less dense than water
their biomass B. remove particles that are more dense than water
D. the rate of cell death C. remove the pertinacious material from the water
D. none of the above
71. The height to diameter ratio (H/D) for the tank fermenters
is 81. Which category of enzymes belongs to class two in the
A. <3 C. <1.5 international classification?
B. >3 D. >1.5 A. Hydrolases C. Transferases
B. Ligases D. Isomerase
72. A reactor has a total volume of 50,000 litres. If it has a
headspace volume of 10,000 litres, then volume of liquid 82. Which of the following common drugs is not a specific
in the reactor will be enzyme inhibitor?
A. 10,000 L C. 30,000 L A. Iodine C. Sulfbnilamide
B. 20,000 L D. 40,000 L B. Methotrexate D. Penicillin

73. If the stirrer speed is too slow, bubbles will accumulate 83. Soya off flavour removal may be achieved using
and coalescese under the impeller. This phenomenon is A. di acetyl reductase C. aldehyde oxidase
known as a B. β- amylase D. protease
A. coalesced impeller C. river impeller
B. flooded impeller D. dry impeller 84. Which of the enzyme combination is commercially used
for the removal of oxygen?
74. In a two-phase system where the continuous phase A. Glucose oxidase-cellulase
remains in place, the gas hold up can be expressed as B. Glucose oxidase-catalase
(where Vs and Vt are the superficial gas velocity and C. Glucose oxidase-lactase
bubble rise velocity) D. All of these
A. H = Vs/(Vs-Vt) C. H = Vs/(Vs.Vt)
B. H = Vs/(Vs+ Vt) D. H = (Vs+Vt)/Vs 85. Saccharomyces cerevisiae produces high biomass yields
at low glucose concentrations and high dissolved oxygen
75. The approach which is commonly used to determine the concentrations. Which of the following should be followed
level of damage to animal cells in a culture medium is to for maximizing its biomass productivity?
monitor A. Batch fermenter with a high initial glucose
A. the concentration of lactate in the medium concentration
B. the level of lactate oxidase activity in the medium B. Continuous fermenter with a low initial glucose
C. the level of lactate dehydrogenase activity concentration
D. the level of lactase activity in the medium C. Fed batch fermenter
D. All of the above
76. Which of the following affect the Kolmogorov eddy size?
A. Stirrer speed 86. The cellular productivity in a continuous stirred tank
B. Physical properties of the liquid fermenter (CSTF) increases with an increase in the
C. Size and type of impeller dilution rate and reaches a maximum value. If the dilution
D. All of these rate is increased beyond the maximum point, the
productivity will
77. Model proposed by the Friedlander, correlating the air A. decrease abruptly C. increase drastically
filtration efficiency by impaction can be expressed as B. increase D. be zero
(where NSt is the Stokes number)
A. ηimp = 0.075 NSt1.2 C. ηimp = 0.25 NSt1.2 87. Pseudo-steady state in a continuous reactor refers to a
B. ηimp = 0.75 NSt 1.2 D. ηimp = 0.025 NSt1.2 reactor in which
A. Pseudomonads are being cultured
78. The collection efficiency by impaction increases with B. concentration oscillate around a mean value
 BIOCHEMISTRY

C. concentration increase with time

D. concentration decrease with time 96. Sterilization can be carried out by
A. heat C. chemical agents
88. Stirred tank fermenter (STF) can be employed for B. radiation D. all of these
A. aerobic fermentation of a wide range of cells
including microbial, animal and plant cells 97. The collection efficiency by the inertial impaction
B. anaerobic fermentation of a wide range of cells mechanism is the function of
including microbial, animal and plant cells A. Stokes and Reynolds number
C. Both (a) and (b) B. Stokes and Schmidt number
D. anaerobic fermentation of plant cells only C. Grashoff and Reynolds number
D. Stokes and Grashof number
89. Residence time distribution (RTD) of a reactor is
independent of 98. The interception efficiency can be expressed as (where
A. micro mixing C. height of the reactor dp is the particle diameter and Dc cylindrical collection
B. volume of reactor D. width of the reactor diameter)
A. dp/Dc C. dp/Dc x 100
90. In the design of a paddle agitator, the ratio of paddle B. dp x Dc D. dpDc/100
diameter to tank diameter is normally taken as
A. 0.1 C. 0.25 99. The deviation from ideal plug flow due to axial mixing can
B. 0.8 D. 0.5 be described by the
A. dispersion model
91. Which of the following stirrer requires least amount of B. Langmuir model
energy for same yield? C. Friedlander model
A. Mig C. Turbine D. Pasceri model
B. Intermig D. Disc
100. In antibiotic manufacturing processes, the fermentation
92. A cylindrical reactor has a liquid volume of 100,000 litres. time ranges from
It has an aspect ratio the ratio of the channel height to A. 2-3 weeks C. 4-5 weeks
width of 1:1. The height of the liquid in the reactor will be B. 1-2 weeks D. 2-4 weeks
approximately:
A. 1.0 m C. 5.0 m 101. In a Lineweaver-Burk Plot, competitive inhibitor shows
B. 3.0 m D. 7.0 m which of the following effect?
A. It moves the entire curve to right
93. The dynamic technique is based on the B. It moves the entire curve to left
A. oxygen material balance in an aerated batch C. It changes the x-intercept
fermenter during the growth of microorganisms D. It has no effect on the slope
B. change of the oxygen concentration
C. oxidation of the sodium sulfite to sodium sulfate 102. To measure the extent to which the reaction rate is
D. oxygen material balance in a fermenter lowered because of resistance to mass transfer, the
effectiveness factor of an immobilized enzyme, η can be
94. The effect of increasing the stirrer speed in an unbaffled defined as
stirred tank reactor is that A. reaction rate/rate if not slowed by diffusion
A. a small increase in stirrer speed will cause the liquid B. rate if not slowed by diffusion/ reaction rate
to enter the turbulent flow regime C. actual reaction rate/ rate if not slowed by
B. as the stirrer speed increases, the liquid will continue diffusion
to circulate and then become turbulent D. rate if not slowed by diffusion/ actual reaction rate
C. as the stirrer speed increases, the liquid will
continue to circulate. Eventually a vortex will 103. Fluidized bed bioreactors provide higher mass transfer
form. rates than packed bed bioreactors because
D. A vortex will form at low stirrer speeds. As the stirrer A. mixing is higher in fluidized bed bioreactors
speed increases the liquid will start to circulate B. particles move with the fluid in a fluidized bed
bioreactor
95. Which of the following is correct? C. immobilized particles are smaller in the fluidized bed
A. The viscosity of liquids and gases decrease with bioreactors
increasing temperature D. all of the above
B. The viscosity of liquids and gases increase with
increasing temperature 104. Yield coefficient represents
C. the viscosity of gases increases with increasing A. total biomass or product produced
temperature, but decreases in liquids B. conversion efficiency of a substrate into product
D. the viscosity of gases decreases with increasing C. conversion rate of a substrate into biomass or
temperature, but decreases in liquids. product
 BIOCHEMISTRY

D. production time of biomass or product D. concentrate shear forces near the disengagement
zone
105. Which of the following would not be subjected to the
"glucose effect"? 113. Which of the following impellers will provide radial flow?
A. Aspergillus fumigatus A. Paddles
B. Saccharomyces cerevisiae B. Flat blade turbines
C. Escherichia coli C. Disk flat blade turbines
D. Aspergillus niger D. All of the above

106. Toxins accumulated in a reactor can lead to low biomass 114. To increase the oxygen transfer rate in a shake flask
yields probably due to which of the following? culture system, which of the following (s) is/are followed?
A. NAD+ is diverted away from homeostasis to A. Liquid volume in the flask is reduced
anabolism B. Stirrer speed is increased
B. ATP is diverted away from homeostasis to C. Baffled flasks are used
anabolism D. All of the above
C. NAD+ is diverted away from anabolism to
homeostasis 115. During aeration, a cylindrical reactor had a height of 10
D. ATP is diverted away from anabolism to m. Without aeration, the height was 7.5 m. Under these
homeostasis aeration and mixing conditions, the gas hold up in the
reactor is
107. In the batch-fed mode, substrate will be added A. 100% C. 50%
A. only at the beginning of the fermentation process B. 75% D. 25%
B. periodically throughout the fermentation process
C. only at the end of the fermentation process 116. The power required by an impeller in a gas sparged
D. substrate is never added system compare to the power required by impeller
operating at same speed in a gas free liquid is usually
108. A strain of Escherichia coli has a maximum specific A. lesser
growth rate of 0.8 h-1 on a glucose based medium. If this B. higher
organism is being grown in a chemostat with a dilution C. same
rate of 1.2 h-1, then at steady state the concentration of D. may be lesser or higher depending upon the
E. coli in the same medium will geometry
A. increase C. change randomly
B. be zero D. decrease 117. The mechanical means of accomplishing sterilization of
fermentation media/equipment is
109. Which of the following is best described as secondary A. ultrasonic
metabolite? B. radiation
A. Acetic acid produced from the oxidation of ethanol C. chemical agents
B. Ethanol from the fermentation of glucose D. none of these
C. Penicillin
D. Citric acid from the partial oxidation of glucose 118. Analogus to the molecular diffusion, the x-directional flux
of microorganisms suspended in a medium due to the
110. The contents in jet loop reactor are mixed through axial mixing can be represented as (where Jn is flux
A. compressed air component 'n', cn is concentration of 'n')
B. a mechanical agitator A. Jn = -dcn/dx C. Jn = -D dcn/dx
C. external pumping B. Jn = dcn/dx D. Jn = D dcn/dx
D. any of these
119. The heat conduction in dry air is
111. Wash out in steady state fermentation occurs when A. less rapid than in steam
A. dilution rate is less than maximum specific growth B. more rapid than in steam
rate C. similar to steam
B. dilution rate is higher than the maximum specific D. none of these
growth rate
C. cell concentration reaches the maximum 120. Which of the following chemical is sometime added in
D. specific growth rate is maximum the process of coagulation and flocculation?
A. Aluminum sulphate C. Calcium chloride
112. The main function(s) of a draft tube in an air lift fermenter B. Aluminum oxide D. None of these
is/are to
A. increase the solubility of oxygen 121. For an enzyme that displays Michaelis-Menten kinetics,
B. distribute shear forces throughout the reactor the reaction velocity (as a fraction of Vmax) observed at
and minimise bubble coalescence [S] = 2 KM will be
C. concentrate shear forces around the sparger A. 0.09 C. 0.66
 BIOCHEMISTRY

B. 0.33 D. 0.91
130. Axial flow impellers
122. Which of the following step is assumed to be the slowest A. provide high shear conditions for breaking up
step in the Michaelis Menten equation? bubbles
A. The substrate consuming step B. provide low shear conditions and are suited for
B. The product releasing step use in shear sensitive processes
C. Formation of enzyme substrate complex C. provide direct flow towards the walls of the reactor
D. None of these D. none of the above

123. A classical noncompetitive inhibitor has 131. In a bioreactor, if at a particular time the oxygen transfer
A. no effect on substrate binding rate is 23 kg.h-1, then the oxygen uptake will be
B. no effect on substrate binding and vice versa A. 23 kg.h-1 C. greater than 23 kg.h-1
C. significant effect on substrate binding B. less than 23 kg.h-1 D. 2.3 kg.h-1
D. significant effect on substrate binding and vice versa
132. Bubble free aeration systems requires
124. Predominantly uncompetitive inhibition may be called A. silicone tubing or gas permeable membranes to
when facilitate gas transfer
A. competitive inhibition is greater than B. carbon dioxide instead of air to supply oxygen
uncompetitive inhibition C. silicone tubing or gas permeable membranes to
B. competitive inhibition is smaller than uncompetitive remove carbon dioxide by oxygen in the form of
inhibition hydrogen peroxide
C. competitive inhibition is equal to uncompetitive D. filled headspace of the reactor with carbon dioxide
inhibition
D. none of the above 133. If the viscosity of a fluid decreases with increasing stirrer
speed, then the nature of the fluid is
125. The lowest biomass yield in a culture of Escherichia coli A. newtonian C. dilatant
will be in B. pseudoplastic D. thixotropic
A. an aerated batch culture containing a initial high
concentration of glucose 134. Water is a
B. an aerated batch reactor containing an initial low A. newtonian fluid C. dilatant
concentration of glucose B. pseudoplastic D. rheopectic
C. an aerated fed-batch reactor having a low glucose
concentration 135. The relationship between the del factor, temperature and
D. an aerated continuous reactor having a low glucose time is given as
concentration A. Δ = A.t. e-E/RT
B. Δ = 1/(A.t. e-E/RT)
126. Power number is ratio of C. Δ = A.t. eE/RT
A. imposed forced to intertial force D. Δ = A.t.T
B. bouyant force to inertial force
C. gravitation force to inertial force 136. Which of the following is considered as a pretreatment
D. imposed force to gravitational force to the biological feeds?
A. Heating to denature the proteins
127. Power number (Np) is also known as B. Addition of filter aids to increase the porosity
A. Froude's number C. Newton's number C. Addition of electrolytes
B. Bond's number D. Rayleigh's number D. All of the above

128. A fermentation system has a KLa of 3 s-1 and a C*0 of 5 137. Conventional adsorption is a
ppm of O2. If the bulk liquid is completely depleted of A. reversible process
oxygen, then the oxygen transfer rate will be equal to B. irreversible process
A. zero C. 10 mg.L-1.s-1 C. either reversible or irreversible
B. 15 mg.L-1.s-1 D. 5 mg.L-1.s-1 D. none of these

129. The power required by an agitator operating in a gas- 138. Which of the operation does not come under upstream
sparged system is processing?
A. lesser than the power required by an impeller in A. Media preparation
operating at same speed in a gas free system B. Inoculum development
B. more than the power required by an impeller in C. Effluent treatment
operating at same speed in a gas free system D. Storage of raw material
C. same as the power required by an impeller in
operating at same speed in a gas free system 139. Sanitizers used for rubber made equipments are
D. none of the above A. strong acids C. combination of both
 BIOCHEMISTRY

B. strong alkalis D. none of these

148. If the specific growth rate, μ. is constant with time during
140. The common methods used for disinfection in waste the exponential growth period, the equation correlating
water treatment plants are bacterial number density Cn), cell number concentration
A. chlorination C. both (a) and (b) with respect to time can be expressed as
B. UV light D. Phenolic solvent A. Cn= Cn0 exp[μ (t - t0)]
B. Cn0 = Cn exp[μ (t - t0)]
141. In competitive inhibition a factor is obtained from the C. Cn/Cn0 =(1/μ)exp(t - t0)
measurement of D. Cn0 /Cn = (1/μ)exp(t - t0)
A. Vmax
B. KM 149. Swirling and vortex formation can be prevented by
C. Y-intercept in Lineweaver-Burk A. using baffles
D. Plot None of these B. using diffusion ring with turbines
C. both (a) and (b)
142. Which of the following is taken as an assumption in the D. none of these
distributed model?
A. The reaction occurs at every position and the 150. Which of the following type(s) of stirrer can be used for
kinetics of the reaction are of the same form as microbiological processes?
observed for free enzyme. A. Mig C. Turbine
B. Mass transfer through the immobilized enzyme B. Intermig D. All of these
occurs via molecular diffusion
C. There is no mass transfer limitation at the outside 151. The average concentration of oxygen in the boundary
surface of the spherical immobilized enzyme layers surrounding the bubbles (Co*) in a reactor is
D. All of the above normally determined by
A. ultra-small dissolved oxygen probes
143. A fed-batch reactor initially contains 2 litre of medium. If B. laser based photographic systems
it was fed at 1 litre per hour, then after 10 hours, the C. measuring the steady state concentration of
volume of the reactor will be oxygen in the bulk liquid prior to inoculation of
A. 1 litre C. 3 litre the reactor
B. 2 litre D. 13 litre D. measuring the steady state concentration of oxygen
in the bulk liquid after inoculation of the reactor
144. In a fluidized bed reactor mixing is achieved by
A. gravity flow of fluid 152. The oxygen uptake requirements of a microbial
B. upward movement of the incoming feed population is characterized by the following parameters:
C. diffusion μm = 0.2 h-1, K0 = 0.2 mg O2.l-1, Y0 = 0.5 mg dry weight/mg
D. both (a) and (b) O2 and C0,crit = 0.8 mg.l-1 The required concentration of
cells is 1000 mg.l-1 and the saturation oxygen
145. Saccharomyces cerevisiae when grown in high glucose concentration of the medium is 5.8 mg.l-1. The required
concentration medium, the cells activity depends on KLa must be greater than
which of the following? A. 64 h-1 C. 16 h-1
A. High concentration of dissolved oxygen B. 32 h-1 D. 8h-1
B. Low concentration of dissolved oxygen
C. No effect of dissolved oxygen 153. Which of the following would be best described as a
D. High concentration of dissolved oxygen and sodium radial flow impeller?
salts A. An impeller with blades pitched at 45° to the vertical
B. A Rushton turbine
146. Which of the following is not correct for the Monod model C. Both (a) and (b)
and the Michaelis Menten Model? D. An impeller which directs liquid flow towards the
A. The Michaelis Menten Model was derived from a base of the reactor
curve fitting exercise
B. The Michaelis Menten model was derived from an 154. The advantage of axial flow impellers over radial flow
analysis of the mechanism of microbial growth impellers is that axial flow impellers
C. The Monod model was derived from an analysis A. provide better lift of solids
of the mechanism of microbial growth B. provide high shear conditions
D. All of the above C. provide low shear conditions
D. are cheaper to build
147. The dilution rate, D is defined as(where F = volumetric
flow rate, VR = total volume of culture in the reactor and 155. Which of the following describes the importance of the
μ specific growth rate) Kolmogorov eddy size in the biotechnology?
A. F/VR C. μ/F A. The Kolmogorov eddy size is a measure of the
B. VR/F D. F/μ smallest eddy size in a liquid
 BIOCHEMISTRY

B. When the Kolmogorov eddy size become equivalent A. 0.115 C. 0.093

or smaller than the cell or particle diameter, then the B. 0.42 D. 6.693
cell or particle will become susceptible to shear
damage 164. When [S] = 0.1*KM, the velocity of an enzyme catalyzed
C. At the Kolmogorov eddy size, much of the energy of reaction is about:
the originating eddy will be released A. 0.1 * Vmax C. 0.5 * Vmax
D. All of the above B. 0.3 * Vmax D. 0.7 * Vmax

156. The viscosity of a fluid changes with either stirrer speed 165. Which of the following are the commonly employed
or mixing time. But when mixing ceases, the viscosity adsorbents?
returns to its original state. This fluid is best described as A. Calcium carbonate C. Celluloses
A. newtonian C. viscoelastic B. Alumina D. All of these
B. rheopectic D. thixotropic
166. The effectiveness factor increases with the
157. The collection efficiency by diffusion increases with A. increase of diffusivity and decreased with the
A. decreasing particle size increase of particle size
B. decreasing air velocity B. increase of diffusivity and increased with the
C. both (a) and (b) increase of particle size
D. increasing particle size C. decrease of diffusivity and decreased with the
increase of particle size
158. The X90 value for a filtration system is D. increase of diffusivity and decrease with the
A. the time required to reduce microbial population by decrease of particle size
90%
B. the time required to traverse survivor curve by one 167. Enzymes act as antimicrobials
log cycle. A. by depriving an organism of a necessary metabolite
C. the depth required to reduce population by 90% B. by generating a substances toxic to the organism
D. the depth of the filter required to reduce population C. by attracting a cell wall component
by 99% D. all of the above

159. The activated sludge process consists of returning a 168. Chymosin hydrolyses the bond between
portion of the clarifier A. Alanine and glycine
A. effluent water entering the reactor B. Phenyl alanine and methonine
B. influent water coming out of the reactor C. Glutamic acid and alanine
C. influent water entering the reactor D. Alanine and phenyl alanine
D. effluent water coming out of the reactor
169. Mixing profiles closest to plug flow are observed in
160. Coliform bacteria in water is an indication of the A. continuous packed bed reactor
presence of B. stirred tank reactor with biomass recycles
A. radioactive wastes C. continuous fluidized bed bioreactor
B. excess fertilizer D. all of these
C. decaying animals and plants
D. human feces 170. In an airlift bioreactor, the air sparging region is called
A. downcomer C. air riser
161. The conformational change in an enzyme after the B. disengagement zone D. none of these
substrate is bound that allows the chemical reaction to
proceed, can be explained by 171. A flooded impeller will lead to poor oxygen transfer rates
A. induced fit C. fit and fine because
B. transition D. Pasteur A. bubbles tend to coalesce under the impeller
B. bubbles tend to break down too rapidly under high
162. The rate-determining step of Michaelis Menten kinetics shear conditions
is C. bubbles tend to move too quickly through the bulk
A. the complex formation step liquid
B. the complex dissociation step to produce D. the cells clog up the surface of the bubble
product
C. the product formation step 172. Surface renewal theory predicts that the mass transfer
D. Both (a)and(c) coefficient is
A. directly proportional to the square root of the
163. An enzyme is assayed at an initial substrate molecular diffusivity
concentration of 2 x 10-5M. In 6 minute, half of the B. inversely proportional to the square root of the
substrate is used. The Km for the substrate is 2 x 10-3M. molecular diffusivity
The value of k in minute is
 BIOCHEMISTRY

C. directly proportional to the cube root of the molecular

diffusivity 181. If a reaction occurs in the absence of inhibitor with rate
D. indirectly proportional to the cube root of the ν0 and in the presence of inhibitor with rate νi, the degree
molecular diffusivity of inhibition is defined as
A. (ν0 - νi)/ν0 C. (ν0νi)/ν0
173. A cylindrical reactor fitted with Rushton Turbine has a B. (ν0 + νi)/ν0 D. (ν0-νi)/νi
liquid volume of 100,000 litres. It has an aspect ratio (the
ratio of the channel height to the width) of 2:1. The 182. Various techniques are available for determining the
diameter of the impeller should be approximately: effective diffusivity of solute in gel. Thin disk method uses
A. 1.3 m C. 5.3 m A. a diffusion cell with two compartments divided
B. 3.3 m D. 7.3 m by a thin gel
B. a diffusion cell with two compartments
174. What is the effect of the concentration of dissolved salts C. a diffusion cell with two compartments plus by a thin
and sugars on the oxygen transfer rate? gel
A. The saturation concentration of oxygen in the D. a diffusion cell with two compartments multiply by a
medium decreases with the concentration of thin gel
dissolved salts and sugars, leading to a lower
oxygen transfer rate 183. The enzyme β-galactosidase is also known as
B. The KLa of the medium decreases with the A. lactase C. both (a) and (b)
concentration of dissolved salts and sugars, leading B. EC3.2.1.23 D. isomerase
to a lower oxygen transfer rate T
C. he KLa of the medium increases with the 184. The main reason for production of antibiotics in fed batch
concentration of dissolved salts and sugars, leading reactors is
to a lower oxygen transfer rate A. the presence of precursors is often toxic to the cells
D. None of the above B. higher yields when cells enter the stationary phase
C. higher yields when cell growth slows
175. Filamentous fungal cells are more shear sensitive than D. all of the above
bacterial cells because of
A. the presence of citin in cell walls of filamentous fungi 185. Which of the following is used to calculate mass of
B. larger in size than bacterial cells and therefore are substrate in the reactor?
more susceptible to shear forces A. Flow rate x substrate concentration in the reactor
C. fungal cells are much larger than bacterial cells B. Volume of reactor x substrate concentration in
D. all of the above reactor
C. Flow rate x mass of reactor
176. A liquid is flowing at 11,400 l.h-1 along a pipeline having D. Volume of reactor x Flow rate
a diameter of 4 cm. If the liquid has a density of 1 g.ml-1
and viscosity of 0.001kg.m-1.s-1, then the liquid would be 186. The fastest route of NADH reoxidation is
in the A. aerobic respiration C. fermentation
A. laminar phase C. turbulent phase B. anaerobic respiration D. decomposition
B. transient phase D. any of the phase
187. Which of the following organisms will continue their
177. For laminar flow of Newtonian fluid through a smooth metabolism at high substrate concentrations?
round pipe, the ratio of average fluid velocity to the A. Pseudomonas aeruginosa
maximum velocity is B. Saccharomyces cerevisiae
A. 0.5 C. 0.87 C. Bacillus subtilis
B. 0.75 D. 0.37 D. Escherichia coli

178. Both temporary and permanent hardness of water can 188. During the exponential phase the maximum specific
be removed on boiling water with growth rate equals specific growth rate as
A. calcium hydroxide C. calcium oxide A. concentration of the growth limiting substrate is
B. sodium carbonate D. calcium carbonate much less than the monod constant
B. concentration of growth limiting substrate is
179. Inhibitors are used along with sanitizer much greater than the monod constant
A. to improve their action C. specific growth rate increases exponentially
B. to prevent corrosion D. concentration of the growth limiting substrate is
C. both (a) and (b) equal to the monod constant
D. none of these
189. The region of an airlift bioreactor in which the liquid
180. Lagoons may be characterized as travels in a downward direction is called the
A. anaerobic C. aerated A. downcomer C. air riser
B. facultative D. all of these B. disengagement zone D. flotsam
 BIOCHEMISTRY

C. 1 - ( ηimpηint/ηdif)
190. The function of the disengagement zone in an airlift D. None of the above
fermenter is to
A. prevent CO2 rich bubbles from entering the 199. The maximum desirable limit (BIS of mercury in the
downcomer drinking water is
B. reduce the velocity of the bubbles r A. 0.05 mg/L C. 0.1 mg/L
C. educe liquid loss as aerosols B. 0.9 mg/L D. 0.001 mg/L
D. all of the above
200. Conventional tertiary treatment is
191. An open system in which the growth rate is maintained A. chemical coagulation and flocculation
by adding a nutrient (present in limiting quantities) at the B. filtration
same rate as that medium containing microorganisms is C. sedimentation
removed is called D. none of these
A. manostat C. turbidostat
B. chemostat D. culturostat

192. The specific growth rate is affected by

A. substrate concentration
B. product concentration
C. oxygen supply
D. all of these

193. In a batch reactor specific growth rate

A. remains constant throughout the process
B. increases exponentially
C. changes during the fermentation
D. is highest during the stationary phase

194. To describe components of an airlift bioreactor which of

the follow-ings are generally included?
A. Disengagement zone, air riser, downcomer
B. Flotsam, jetsam, downzone
C. Air comer, disentanglement zone, downsizer
D. All of the above

195. A fermentation system has a KLa of 3 s-1 and a C*o of 5

ppm of O2. If the bulk liquid is saturated with oxygen then
the oxygen transfer rate will be equal to
A. zero C. 5 mg*L-1*s-1
B. 3 mg*L-1*s-1 D. 15 mg*L-1*s-1

196. Higher temperatures affect oxygen transfer rates by

A. increasing KLa but lowering C*o
B. lowering KLa but increasing C*o
C. increasing KLa and increasing Co
D. lowering KLa and lowering Co

197. A rheopectic fluid is one in which the viscosity

A. is constant regardless of the stirrer speed or mixing
time
B. changes during mixing but returns to its original state
after mixing
C. increases with mixing time
D. decreases with mixing time

198. The efficiency of fibrous filter by combined mechanism is

given by(where ηimp, ηint, ηdif are the efficiencies by
impaction, interception and diffusion respectively)
A. 1 - ηimpηintηdif
B. 1 - (1 - ηimp)(1 - ηint)(1 - ηdif)