BIOCHEMISTRY

C. the government will not approve the

BIOCHEMISTRY licensing of pharmaceuticals produced in
continuous cultures
D. all of the above
1. Which of the following statements is not true?
A. Enzymes are proteins that bind to specific 9. Production of organic acids in batch culture is
substrates and increase the velocity of generally a growth associated phase followed by
reactions involving those substrates non-growth associated production. The probable
B. Enzymes function by overcoming the reason for this is that
activation energy barrier of a reaction A. organic acids uncouple catabolism from
C. Enzymes make thermodynamically favorable anabolism
reactions to proceed; they cannot make B. biomass yields increase as the
unfavorable reactions to occur fermentation proceeds
D. Enzymes only function when they are in intact C. organic acids are secondary metabolites
cells D. high concentrations of organic acid
promote the growth of the microbial
2. An enzyme and a reactant molecule maintain population
relationship as
A. a temporary association 10. Biomass concentrations during fermentation is
B. an association stabilized by a covalent bond A. diluting the samples to optical density less than
C. one in which the enzyme is changed 0.3
permanently B. monitored by controlling the changes in
D. non complementary binding biomass concentrations
C. considering that optical density is
3. The active site of an enzyme proportional to the surface area of the
remains biomass in the sample
A. at the center of globular D. all of the above
proteins
B. rigid and does not change shape
11. Turbine impeller consists of flat impeller blades with
C. complementary to the rest of the molecule
A. a vertical pitch welded directly to the shaft
D. none of the above
B. a angled pitch welded directly to the shaft
C. a vertical pitch welded to
4. A classical uncompetitive inhibitor is a
D. a horizontal disk a angled pitch welded
compound that binds
to a horizontal disk
A. reversibly to the enzyme substrate complex
yielding an inactive ESI complex
12. At 25°C, the saturation concentration of oxygen
B. irreversibly to the enzyme substrate
in water is 1.26 mmol/l and the partial pressure
complex yielding an inactive ESI complex
of oxygen is 1 atm. The Henry's law constant will
C. reversibly to the enzyme substrate complex
be
yielding an active ESI complex
A. 0.793 atml/mmol C. 1.26 atml/mmol
D. irreversibly to the enzyme substrate
B. 0.207 atml/mmol D. 8.74 atml/mmol
complex yielding an active ESI complex
13. Small propellers turn at the speed of either
5. The types of inhibition pattern based on
A. 20 or 150 rpm C. 400 or 800 rpm
Michaelis Menten equation are
B. 150 or 300 rpm D. 1150 rpm or 1750
A. competitive C. uncompetitive
rpm
B. non-competitive D. all of the above
14. Which of the following models holds correct for
6. Milk digestibility is improved by using
the two- film theory? (where KL is the mass
A. RNase C. β-amylase
transfer coefficient, DAB diffusivity and Zf film
B. lactase D. none of these
thickness)
A. KL = DAB/Zf C. KL= Zf/DAB
7. Which of the following metallic ion is there in
ascorbic acid oxidase? B. KL = DAB D. KL = DAB*Zf
A. Mg C. Cu
B. Fe D. Mn 15. Pluronic F68 is added to cell culture media as
A. a nutrient
8. The continuous cultures are not widely used in B. a shear protectant
industry because C. to increase oxygen transfer rates
A. they are not suited for the production of D. all of these
secondary metabolites
B. contamination or mutation can have a 16. Which of the following can act as a shear protectant?
disastrous effect on the operation A. Serum C. Glucose
 BIOCHEMISTRY

B. Silicone oil D. Glutamic acid

17. For the extractions operation, the selectivity

should be
A. > 1 C. 1
B. < 1 D. zero
 BIOCHEMISTRY

concentration of glucose in the feed is 10 g.l -1 and

18. Permanent hardness of water may be removed the dilution rate is set to 0.4 h -1, then the steady
by the addition of state concentration of glucose in the effluent will be
A. lime C. potassium permagnate
B. soda ash D. sodium bicarbonate

19. Zeolite softening process removes both

temporary and permanent hardness of water. In
this process the calcium and magnesium present
in water are precipitated as
A. insoluble carbonates C.
insoluble
chlorides
B. insoluble zeolites D.
insoluble sulfates

20. The maximum desirable limit (BIS) of total

hardness (as CaCo3) in drinking water is
A. 600 ppm C. 500 ppm
B. 300 ppm D. 1000 ppm

21. Which graphical method is used to determine an

enzyme degree of cooperativity?
A. Hill plot
B. Koshland curve
C. Michaelis-Menten hyperbola
D. Can not be determined

22. The effect of non-competitive inhibition on a

Lineweaver- Burk Plot is that
A. it can move the entire curve to the right
B. it can change the y-intercept
C. it can change the x-intercept
D. all of these

23. Which is not the method for producing

immobilized enzymes with multifunctional
reagents?
A. Enzymes are adsorbed on the surface active
support followed by intermolecular cross
linking
B. Functional groups are introduced on the
support to react co-valently with enzymes
C. Enzymes are cross linked intermolecularly
D. None of the above

24. Commonly employed water insoluble supports

for the covalent attachment of enzyme include
A. acrylamide based polymers
B. polypeptides
C. dextran
D. all of these

25. Discoloration can be achieved by using s

A. ulphloydryl oxidase
B. proteases
C. anthocyanase
D. all of these

26. The growth of an organism on glucose is

described by the following Monod model
parameters: μm = 0.5 h-1 and Ks = 0.1 g.l-1, if the
 BIOCHEMISTRY

A. 0 g.l-1 C. 1.0 g.l-1 A. the saturation concentration of oxygen is higher

B. 0.5 g.l-1 D. 10 g.l-1 B. the bubble size is smaller
C. the oxygen transfer coefficient is larger
27. Continuous culture has an advantage over to D. the partial pressure of oxygen in the gas
a batch cultures as phase is lower
A. continuous reactors do not need to be
shut down and cleaned as regularly as a
batch reactor
B. most downstream and upstream
processes are continuous in nature and
thus the operation of continuous
bioreactor can be better integrated into
the overall manufacturing process
C. cells can be maintained at a constant
physiological state simply by setting the
dilution rate
D. all of the above

28. Which of the following is an example of a

mathematical model?
A. Volume of cuboid = length x breadth x height
B. The Monod Model
C. The Michaelis Menten Equation
D. All of the above

29. A mixed fermentation is one, which produces

A. both alcohol and carbon dioxide
B. both acid and carbon dioxide
C. both acid and alcohol
D. several different kinds of acid

30. Radial flow impellers

A. provide high shear conditions for
breaking up bubbles
B. direct flow towards the walls of the reactor
C. Both (a) and (b)
D. provide low shear conditions and are
suited for use in shear sensitive
procesess

31. Which of the following is not classified as an

axial flow impeller?
A. A propeller C. A Rushton turbine
B. A marine impeller D. A hydrofoil
impeller

32. The maximum solubility of the alkane in the

medium is 5 ppm. If the actual dissolved
concentration of the alkane in the medium is
1 ppm. what conclusion may be drawn?
A. The growth rate is limited by the rate of
mass transfer of the alkane into the
fermentation medium
B. The growth rate is limited by the
intrinsic kinetic properties of the cells
and not by mass transfer
C. The growth rate is neither mass
transfer nor kinetically limited
D. No conclusion on the growth rate can
be withdrawn

33. Pure oxygen, if used instead of air will

increase oxygen transfer rates because
 BIOCHEMISTRY

34. Which of the following impellers generate a flow 44. A continuous reactor has a dilution rate of 0.5
parallel to the axis of shaft?
h-1. Its 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,
45. Which of the following would be correct
another dimensionless number,
concerning the concentration of biomass (X).
is useful.
growth limiting substrate
A. Stanton C. Bond
(S) and product (P) in a chemostat when the cells
B. Rayleigh D. Froude
have 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
A. is constant regardless of the stirrer speed or
above condition
mixing time
C. X and P will be zero while S is equal to the
B. changes during mixing but returns to its substrate concentration in feed
original 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
B. growth rate is equal to death rate
required for a volumetric airflow rate of 10
C. growth rate is lesser than death rate
m3/min is approximately
D. no co-relation exist between death rate and
A. 1.6 m C. 3
growth rate
B. 0.6 m D. 6 m
47. The relatively large volume (10 to 40% of total
38. Maintenance cost varies from
fermenter volume) of the seed culture is
A. 0-4% of the capital cost
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
48. The air riser is located on the outside of the draft
A. 0-5% of the capital cost
tube for the large-scale airlift bioreactors
B. 10-15% of the capital cost
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
C. turning bed biological oxidation system
reactor are 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
A. continuous penicillin production
method 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,
D. ionic bond formation dependent
then the Reynolds number in a stirred tank
reactor will vary with the
43. During the enzymatic reaction of an immobilized A. impeller diameter
enzyme, 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
52. During fermentation, the saturation
consumption
 BIOCHEMISTRY

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 60. Application of quaternary ammonium
oxygen concentration is lesser than the compounds as sanitizing agents tends to
saturation concentration
A. favor gram positive bacteria
B. Microbial growth is not oxygen limited since B. decrease gram positive bacteria
the oxygen concentration is lesser than the
C. increase the percentage of gram(-)ve rods on
saturation 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
53. The best described action of Pluronic F68 (non- by transferases?
ionic detergent) in a cell culture medium is that, A. Transfer of methyl groups
it
B. Transfer of glycosyl group
A. acts on the surface properties of the cells and
C. Both (a) and (b)
the culture medium D. None of these
B. provides nutrients for the cells
C. acts as a flocculant
62. The active site of an enzyme differs from an
D. acts as a coagulant
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
-1 -1
B. 0.001 kg*m *s D. 0.1 g*cm-1*s-1 simple enzyme reaction is given by (Where rmax,
maximum reaction rate, Cs substrate
56. The viscosity of the culture fluid is classified as concentration, Cp product concentration ES, CES
both pseudoplastic and thixotropic which enzyme-substrate concentration)
indicates that the viscosity A. rp = rmax Cs/(Km + Cs)
A. increases with stirring speed but decreases B. rp = rmax CES/(Km+ CES)
with mixing time C. rp = rmax Cs/(Km + CES)
B. increases with stirring speed and increases D. rp = rmax Cs/(Km + Cp)
with mixing time
C. decreases with stirring speed but increases
64. The slope of Lineweaver Burk plot for Michaelis
with mixing time Menten equation is
D. decreases with stirring speed and decreases
A. Vmax/Km C. 1/Km
with mixing time
B. Km/Vmax D. Km.Vmax
57. The mechanism of air filtration in fibrous filter is
65. Which is true about rennet?
A. electrostatic attraction
A. It is a mixture of protease chymosin and pepsin
B. impaction
B. It is a mixture of rennin and pepsin
C. interception
C. Both (a) and (b)
D. all of these
D. none of the above
58. The correlation often employed to correlate
66. The enzyme used to reduce bitterness of
adsorption data for protein is (where Ymax is the
grapes commonly contains
maximum amount of solute adsorbed per mass
A. α-L-rhamonosidase C. β- galactosidase
of adsorbent, X is the mass fraction of solute in
B. β-d-glucosidase D. both (a) and (b)
the diluent phase in solute-free basis, KL is a
constant and Y is the equilibrium value of the 67. A culture system with constant environmental
mass of solute adsorbed per mass of adsorbent) conditions maintained through continual
A. Y = YmaxX/(KL+X) C. Y = YmaxX/KL provision of nutrient and removal of wastes is
B. Y= Ymax/(KL+X) D. Y = Ymax- X/(KL+X) called culture
system.
59. Zeolite used in zeolite softening process for the A. continuous C. fed-batch
treatment of hard water gets exhausted after B. batch D. semi continuous
certain time of usage but can be regenerated by
flushing it with 68. When two populations compete for a single
A. 10% calcium chloride solution growth limiting substrate in a continuous
B. 10% magnesium sulfate solution fermenter, which organism would not be washed
C. 10% magnesium chloride solution out?
D. 10% sodium chloride solution A. Organism maintaining the highest substrate
 BIOCHEMISTRY

concentration
B. Organism maintaining the lowest substrate
concentration
C. Both (a) and (b)
 BIOCHEMISTRY

D. Organism maintaining the moderate 78. The collection efficiency by impaction increases with
substrate concentration

69. Low dissolved oxygen concentrations leads to

A. low biomass yields
B. high biomass yields
C. no effect on biomass yields
D. none of the above

70. The specific growth rate (μ) is defined as

A. the concentration of biomass in the reactor
B. rate of increase of total biomass in a reactor
C. the rate of individual cells division or increase
in their biomass
D. the rate of cell death

71. The height to diameter ratio (H/D) for the tank

fermenters is
A. <3 C. <1.5
B. >3 D. >1.5

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 in the reactor will be
A. 10,000 L C. 30,000 L
B. 20,000 L D. 40,000 L

73. If the stirrer speed is too slow, bubbles will

accumulate and coalescese under the impeller.
This phenomenon is known as a
A. coalesced impeller C. river impeller
B. flooded impeller D. dry impeller

74. In a two-phase system where the continuous

phase remains in place, the gas hold up can be
expressed as (where Vs and Vt are the superficial
gas velocity and bubble rise velocity)
A. H = Vs/(Vs-Vt) C. H = Vs/(Vs.Vt)
B. H = Vs/(Vs+ Vt) D. H = (Vs+Vt)/Vs

75. The approach which is commonly used to

determine the level of damage to animal cells in
a culture medium is to monitor
A. the concentration of lactate in the medium
B. the level of lactate oxidase activity in the
medium
C. the level of lactate dehydrogenase activity
D. the level of lactase activity in the medium

76. Which of the following affect the Kolmogorov

eddy size?
A. Stirrer speed
B. Physical properties of the liquid
C. Size and type of impeller
D. All of these

77. Model proposed by the Friedlander, correlating

the air filtration efficiency by impaction can be
expressed as (where NSt is the Stokes number)
A. ηimp = 0.075 NSt1.2 C. ηimp = 0.25 NSt1.2
1.2
B. ηimp = 0.75 NSt D. ηimp = 0.025 NSt1.2
 BIOCHEMISTRY

A. increasing particle diameter 87. Pseudo-steady state in a continuous reactor

B. increasing air flow velocity refers to a reactor in which
C. both (a) and (b) A. Pseudomonads are being cultured
D. increasing particle size B. concentration oscillate around a mean value

79. The optimum wet solid content for the cell

suspension for a bead mill is typically
somewhere between
A. 5-15% by volume C. 30-60% by volume
B. 15-30% by volume D. 60-90% by volume

80. Sedimentation is a physical process used in

wastewater treatment to
A. remove particles that are less dense than
water
B. remove particles that are more dense than water
C. remove the pertinacious material from the
water
D. none of the above

81. Which category of enzymes belongs to class

two in the international classification?
A. Hydrolases C. Transferases
B. Ligases D. Isomerase

82. Which of the following common drugs is not a

specific enzyme inhibitor?
A. Iodine C. Sulfbnilamide
B. Methotrexate D. Penicillin

83. Soya off flavour removal may be achieved using

A. di acetyl reductase C. aldehyde oxidase
B. β- amylase D. protease

84. Which of the enzyme combination is

commercially used for the removal of
oxygen?
A. Glucose oxidase-cellulase
B. Glucose oxidase-catalase
C. Glucose oxidase-lactase
D. All of these

85. Saccharomyces cerevisiae produces high

biomass yields at low glucose concentrations
and high dissolved oxygen concentrations.
Which of the following should be followed for
maximizing its biomass productivity?
A. Batch fermenter with a high initial
glucose concentration
B. Continuous fermenter with a low initial
glucose concentration
C. Fed batch fermenter
D. All of the above

86. The cellular productivity in a continuous

stirred tank fermenter (CSTF) increases with
an increase in the dilution rate and reaches a
maximum value. If the dilution rate is
increased beyond the maximum point, the
productivity will
A. decrease abruptly C. increase drastically
B. increase D. be zero
 BIOCHEMISTRY

C. concentration increase with time B. The viscosity of liquids and gases increase
D. concentration decrease with time with increasing temperature
C. the viscosity of gases increases with increasing
88. Stirred tank fermenter (STF) can be employed for temperature, but decreases in liquids
A. aerobic fermentation of a wide range of D. the viscosity of gases decreases with
cells including microbial, animal and plant increasing temperature, but decreases in liquids.
cells
B. anaerobic fermentation of a wide range of
cells including microbial, animal and plant
cells
C. Both (a) and (b)
D. anaerobic fermentation of plant cells only

89. Residence time distribution (RTD) of a

reactor is independent of
A. micro mixing C. height of the
reactor
B. volume of reactor D. width of the
reactor

90. In the design of a paddle agitator, the ratio of

paddle diameter to tank diameter is normally
taken as
A. 0.1 C. 0.25
B. 0.8 D. 0.5

91. Which of the following stirrer requires least

amount of energy for same yield?
A. Mig C. Turbine
B. Intermig D. Disc

92. A cylindrical reactor has a liquid volume of

100,000 litres. It has an aspect ratio the ratio of
the channel height to width of 1:1. The height of
the liquid in the reactor will be approximately:
A. 1.0 m C. 5.0 m
B. 3.0 m D. 7.0 m

93. The dynamic technique is based on the

A. oxygen material balance in an aerated batch
fermenter during the growth of microorganisms
B. change of the oxygen concentration
C. oxidation of the sodium sulfite to sodium
sulfate
D. oxygen material balance in a fermenter

94. The effect of increasing the stirrer speed in an

unbaffled stirred tank reactor is that
A. a small increase in stirrer speed will cause
the liquid to enter the turbulent flow regime
B. as the stirrer speed increases, the liquid will
continue to circulate and then become
turbulent
C. as the stirrer speed increases, the liquid will
continue to circulate. Eventually a vortex will
form.
D. A vortex will form at low stirrer speeds. As
the stirrer speed increases the liquid will
start to circulate

95. Which of the following is correct?

A. The viscosity of liquids and gases decrease
with increasing temperature
 BIOCHEMISTRY

biomass or product
96. Sterilization can be carried out by
A. heat C. chemical agents
B. radiation D. all of these

97. The collection efficiency by the inertial

impaction mechanism is the function of
A. Stokes and Reynolds number
B. Stokes and Schmidt number
C. Grashoff and Reynolds number
D. Stokes and Grashof number

98. The interception efficiency can be expressed

as (where dp is the particle diameter and Dc
cylindrical collection diameter)
A. dp/Dc C. dp/Dc x 100
B. dp x Dc D. dpDc/100

99. The deviation from ideal plug flow due to

axial mixing can be described by the
A. dispersion model
B. Langmuir model
C. Friedlander model
D. Pasceri model

100.In antibiotic manufacturing processes, the

fermentation time ranges from
A. 2-3 weeks C. 4-5 weeks
B. 1-2 weeks D. 2-4 weeks

101.In a Lineweaver-Burk Plot, competitive

inhibitor shows which of the following effect?
A. It moves the entire curve to right
B. It moves the entire curve to left
C. It changes the x-intercept
D. It has no effect on the slope

102.To measure the extent to which the reaction

rate is lowered because of resistance to mass
transfer, the effectiveness factor of an
immobilized enzyme, η can be defined as
A. reaction rate/rate if not slowed by diffusion
B. rate if not slowed by diffusion/ reaction rate
C. actual reaction rate/ rate if not slowed
by diffusion
D. rate if not slowed by diffusion/ actual
reaction rate

103.Fluidized bed bioreactors provide higher

mass transfer rates than packed bed
bioreactors because
A. mixing is higher in fluidized bed bioreactors
B. particles move with the fluid in a fluidized
bed bioreactor
C. immobilized particles are smaller in the
fluidized bed bioreactors
D. all of the above

104.Yield coefficient represents

A. total biomass or product produced
B. conversion efficiency of a substrate into
product
C. conversion rate of a substrate into
 BIOCHEMISTRY

D. production time of biomass or product 112.The main function(s) of a draft tube in an air lift
fermenter is/are to
105.Which of the following would not be subjected A. increase the solubility of oxygen
to the "glucose effect"? B. distribute shear forces throughout the reactor and
A. Aspergillus fumigatus minimise bubble coalescence
B. Saccharomyces cerevisiae C. concentrate shear forces around the sparger
C. Escherichia coli
D. Aspergillus niger

106.Toxins accumulated in a reactor can lead to low

biomass yields probably due to which of the
following?
A. NAD+ is diverted away from homeostasis
to anabolism
B. ATP is diverted away from homeostasis
to anabolism
C. NAD+ is diverted away from anabolism
to homeostasis
D. ATP is diverted away from anabolism to
homeostasis

107.In the batch-fed mode, substrate will be added

A. only at the beginning of the fermentation
process
B. periodically throughout the fermentation
process
C. only at the end of the fermentation process
D. substrate is never added

108.A strain of Escherichia coli has a maximum

specific growth rate of 0.8 h-1 on a glucose based
medium. If this organism is being grown in a
chemostat with a dilution rate of 1.2 h-1, then at
steady state the concentration of
E. coli in the same medium will
A. increase C. change randomly
B. be zero D. decrease

109.Which of the following is best described as

secondary metabolite?
A. Acetic acid produced from the oxidation of
ethanol
B. Ethanol from the fermentation of glucose
C. Penicillin
D. Citric acid from the partial oxidation of
glucose

110.The contents in jet loop reactor are mixed

through
A. compressed air
B. a mechanical agitator
C. external pumping
D. any of these

111.Wash out in steady state fermentation occurs

when
A. dilution rate is less than maximum specific
growth rate
B. dilution rate is higher than the maximum
specific growth rate
C. cell concentration reaches the maximum
D. specific growth rate is maximum
 BIOCHEMISTRY

D. concentrate shear forces near the

disengagement zone 121.For an enzyme that displays Michaelis-Menten
kinetics, the reaction velocity (as a fraction of
113.Which of the following impellers will provide Vmax) observed at
radial flow? [S] = 2 KM will be
A. Paddles A. 0.09 C. 0.66
B. Flat blade turbines
C. Disk flat blade turbines
D. All of the above

114.To increase the oxygen transfer rate in a

shake flask culture system, which of the
following (s) is/are followed?
A. Liquid volume in the flask is reduced
B. Stirrer speed is increased
C. Baffled flasks are used
D. All of the above

115.During aeration, a cylindrical reactor had a

height of 10
m. Without aeration, the height was 7.5 m. Under
these aeration and mixing conditions, the gas
hold up in the reactor is
A. 100% C. 50%
B. 75% D. 25%

116.The power required by an impeller in a gas

sparged system compare to the power
required by impeller operating at same speed
in a gas free liquid is usually
A. lesser
B. higher
C. same
D. may be lesser or higher depending
upon the geometry

117.The mechanical means of accomplishing

sterilization of fermentation
media/equipment is
A. ultrasonic
B. radiation
C. chemical agents
D. none of these

118.Analogus to the molecular diffusion, the x-

directional flux of microorganisms suspended
in a medium due to the axial mixing can be
represented as (where Jn is flux component
'n', cn is concentration of 'n')
A. Jn = -dcn/dx C. Jn = -D dcn/dx
B. Jn = dcn/dx D. Jn = D dcn/dx

119.The heat conduction in dry air is

A. less rapid than in steam
B. more rapid than in steam
C. similar to steam
D. none of these

120.Which of the following chemical is sometime

added in the process of coagulation and
flocculation?
A. Aluminum sulphate C. Calcium chloride
B. Aluminum oxide D. None of these
 BIOCHEMISTRY

B. 0.33 D. 0.91 impeller in operating at same speed in a gas free

system
122.Which of the following step is assumed to be the D. none of the above
slowest step in the Michaelis Menten equation?
A. The substrate consuming step
B. The product releasing step
C. Formation of enzyme substrate complex
D. None of these

123.A classical noncompetitive inhibitor has

A. no effect on substrate binding
B. no effect on substrate binding and vice versa
C. significant effect on substrate binding
D. significant effect on substrate binding and
vice versa

124.Predominantly uncompetitive inhibition may be

called when
A. competitive inhibition is greater than
uncompetitive inhibition
B. competitive inhibition is smaller than
uncompetitive inhibition
C. competitive inhibition is equal to
uncompetitive inhibition
D. none of the above

125.The lowest biomass yield in a culture of

Escherichia coli
will be in
A. an aerated batch culture containing a initial high
concentration of glucose
B. an aerated batch reactor containing an
initial low concentration of glucose
C. an aerated fed-batch reactor having a low
glucose concentration
D. an aerated continuous reactor having a low
glucose concentration

126.Power number is ratio of

A. imposed forced to intertial force
B. bouyant force to inertial force
C. gravitation force to inertial force
D. imposed force to gravitational force

127. Power number (Np) is also known as

A. Froude's number C. Newton's number
B. Bond's number D. Rayleigh's number

128. A fermentation system has a KLa of 3 s-1 and a

C*0 of 5 ppm of O2. If the bulk liquid is completely
depleted of oxygen, then the oxygen transfer
rate will be equal to
A. zero C. 10 mg.L-1.s-1
B. 15 mg.L .s-1 -1
D. 5 mg.L-1.s-1

129.The power required by an agitator operating in a

gas- sparged system is
A. lesser than the power required by an impeller in
operating at same speed in a gas free system
B. more than the power required by an
impeller in operating at same speed in a gas
free system
C. same as the power required by an
 BIOCHEMISTRY

D. Storage of raw material

130.Axial flow impellers
A. provide high shear conditions for 139.Sanitizers used for rubber made equipments are
breaking up bubbles A. strong acids C. combination of both
B. provide low shear conditions and are suited
for use in shear sensitive processes
C. provide direct flow towards the walls of the
reactor
D. none of the above

131.In a bioreactor, if at a particular time the

oxygen transfer rate is 23 kg.h-1, then the
oxygen uptake will be
A. 23 kg.h-1 C. greater than 23
kg.h-1
B. less than 23 kg.h-1 D. 2.3 kg.h-1

132.Bubble free aeration systems requires

A. silicone tubing or gas permeable
membranes to facilitate gas transfer
B. carbon dioxide instead of air to supply
oxygen
C. silicone tubing or gas permeable
membranes to remove carbon dioxide by
oxygen in the form of hydrogen peroxide
D. filled headspace of the reactor with carbon
dioxide

133.If the viscosity of a fluid decreases with

increasing stirrer speed, then the nature of
the fluid is
A. newtonian C. dilatant
B. pseudoplastic D. thixotropic

134.Water is a
A. newtonian fluid C. dilatant
B. pseudoplastic D. rheopectic

135.The relationship between the del factor,

temperature and time is given as
A. Δ = A.t. e-E/RT
B. Δ = 1/(A.t. e-E/RT)
C. Δ = A.t. eE/RT
D. Δ = A.t.T

136.Which of the following is considered as a

pretreatment to the biological feeds?
A. Heating to denature the proteins
B. Addition of filter aids to increase the porosity
C. Addition of electrolytes
D. All of the above

137.Conventional adsorption is a
A. reversible process
B. irreversible process
C. either reversible or irreversible
D. none of these

138.Which of the operation does not come under

upstream processing?
A. Media preparation
B. Inoculum development
C. Effluent treatment
 BIOCHEMISTRY

B. strong alkalis D. none of these B. VR/F D. F/μ

140.The common methods used for disinfection in

waste water treatment plants are
A. chlorination C. both (a) and (b)
B. UV light D. Phenolic solvent

141.In competitive inhibition a factor is obtained from

the measurement of
A. Vmax
B. KM
C. Y-intercept in Lineweaver-Burk
D. Plot None of these

142.Which of the following is taken as an

assumption in the distributed model?
A. The reaction occurs at every position and the
kinetics of the reaction are of the same form
as observed for free enzyme.
B. Mass transfer through the immobilized
enzyme occurs via molecular diffusion
C. There is no mass transfer limitation at the
outside surface of the spherical immobilized
enzyme
D. All of the above

143.A fed-batch reactor initially contains 2 litre of

medium. If it was fed at 1 litre per hour, then
after 10 hours, the volume of the reactor will be
A. 1 litre C. 3 litre
B. 2 litre D. 13 litre

144.In a fluidized bed reactor mixing is achieved by

A. gravity flow of fluid
B. upward movement of the incoming feed
C. diffusion
D. both (a) and (b)

145.Saccharomyces cerevisiae when grown in high

glucose concentration medium, the cells activity
depends on which of the following?
A. High concentration of dissolved oxygen
B. Low concentration of dissolved oxygen
C. No effect of dissolved oxygen
D. High concentration of dissolved oxygen and
sodium salts

146.Which of the following is not correct for the

Monod model and the Michaelis Menten Model?
A. The Michaelis Menten Model was derived
from a curve fitting exercise
B. The Michaelis Menten model was derived
from an analysis of the mechanism of
microbial growth
C. The Monod model was derived from an analysis
of the mechanism of microbial growth
D. All of the above

147.The dilution rate, D is defined as(where F =

volumetric flow rate, VR = total volume of culture
in the reactor and μ specific growth rate)
A. F/VR C. μ/F
 BIOCHEMISTRY

D. are cheaper to build

148.If the specific growth rate, μ. is constant
with time during the exponential growth 155.Which of the following describes the importance
period, the equation correlating bacterial of the Kolmogorov eddy size in the
number density Cn), cell number biotechnology?
concentration with respect to time can be A. The Kolmogorov eddy size is a measure of
expressed as the smallest eddy size in a liquid
A. Cn= Cn0 exp[μ (t - t0)]
B. Cn0 = Cn exp[μ (t - t0)]
C. Cn/Cn0 =(1/μ)exp(t - t0)
D. Cn0 /Cn = (1/μ)exp(t - t0)

149.Swirling and vortex formation can be prevented

by
A. using baffles
B. using diffusion ring with turbines
C. both (a) and (b)
D. none of these

150.Which of the following type(s) of stirrer can

be used for microbiological processes?
A. Mig C. Turbine
B. Intermig D. All of these

151.The average concentration of oxygen in the

boundary layers surrounding the bubbles
(Co*) in a reactor is normally determined by
A. ultra-small dissolved oxygen probes
B. laser based photographic systems
C. measuring the steady state concentration of
oxygen in the bulk liquid prior to
inoculation of the reactor
D. measuring the steady state
concentration of oxygen in the bulk liquid
after inoculation of the reactor

152.The oxygen uptake requirements of a

microbial population is characterized by the
following parameters: μm = 0.2 h-1, K0 = 0.2
mg O2.l-1, Y0 = 0.5 mg dry weight/mg O2 and
C0,crit = 0.8 mg.l-1 The required
concentration of cells is 1000 mg.l-1 and the
saturation oxygen concentration of the
medium is 5.8 mg.l-1. The required KLa must
be greater than
A. 64 h-1 C. 16 h-1
-1
B. 32 h D. 8h-1

153.Which of the following would be best

described as a radial flow impeller?
A. An impeller with blades pitched at 45° to the
vertical
B. A Rushton turbine
C. Both (a) and (b)
D. An impeller which directs liquid flow
towards the base of the reactor

154.The advantage of axial flow impellers over

radial flow impellers is that axial flow
impellers
A. provide better lift of solids
B. provide high shear conditions
C. provide low shear conditions
 BIOCHEMISTRY

B. When the Kolmogorov eddy size become 2 x 10-3M. The value of k in minute is
equivalent or smaller than the cell or particle
diameter, then the cell or particle will
become susceptible to shear damage
C. At the Kolmogorov eddy size, much of the
energy of the originating eddy will be
released
D. All of the above

156.The viscosity of a fluid changes with either

stirrer speed or mixing time. But when mixing
ceases, the viscosity returns to its original state.
This fluid is best described as
A. newtonian C. viscoelastic
B. rheopectic D. thixotropic

157.The collection efficiency by diffusion increases

with
A. decreasing particle size
B. decreasing air velocity
C. both (a) and (b)
D. increasing particle size

158. The X90 value for a filtration system is

A. the time required to reduce microbial
population by 90%
B. the time required to traverse survivor curve
by one log cycle.
C. the depth required to reduce population by 90%
D. the depth of the filter required to reduce
population by 99%

159.The activated sludge process consists of

returning a portion of the clarifier
A. effluent water entering the reactor
B. influent water coming out of the reactor
C. influent water entering the reactor
D. effluent water coming out of the reactor

160.Coliform bacteria in water is an indication

of the presence of
A. radioactive wastes
B. excess fertilizer
C. decaying animals and plants
D. human feces

161.The conformational change in an enzyme after

the substrate is bound that allows the chemical
reaction to proceed, can be explained by
A. induced fit C. fit and fine
B. transition D. Pasteur

162.The rate-determining step of Michaelis Menten

kinetics is
A. the complex formation step
B. the complex dissociation step to produce
product
C. the product formation step
D. Both (a)and(c)

163.An enzyme is assayed at an initial substrate

concentration of 2 x 10-5M. In 6 minute, half of
the substrate is used. The Km for the substrate is
 BIOCHEMISTRY

A. 0.115 C. 0.093 root of the molecular diffusivity

B. 0.42 D. 6.693

164. When [S] = 0.1*KM, the velocity of an

enzyme catalyzed reaction is about:
A. 0.1 * Vmax C. 0.5 * Vmax
B. 0.3 * Vmax D. 0.7 * Vmax

165.Which of the following are the commonly

employed adsorbents?
A. Calcium carbonate C. Celluloses
B. Alumina D. All of these

166.The effectiveness factor increases with the

A. increase of diffusivity and decreased with
the increase of particle size
B. increase of diffusivity and increased
with the increase of particle size
C. decrease of diffusivity and decreased
with the increase of particle size
D. increase of diffusivity and decrease
with the decrease of particle size

167.Enzymes act as antimicrobials

A. by depriving an organism of a necessary
metabolite
B. by generating a substances toxic to the
organism
C. by attracting a cell wall component
D. all of the above

168.Chymosin hydrolyses the bond between

A. Alanine and glycine
B. Phenyl alanine and methonine
C. Glutamic acid and alanine
D. Alanine and phenyl alanine

169.Mixing profiles closest to plug flow are observed

in
A. continuous packed bed reactor
B. stirred tank reactor with biomass recycles
C. continuous fluidized bed bioreactor
D. all of these

170.In an airlift bioreactor, the air sparging region is

called
A. downcomer C. air riser
B. disengagement zone D. none of these

171.A flooded impeller will lead to poor oxygen

transfer rates because
A. bubbles tend to coalesce under the impeller
B. bubbles tend to break down too rapidly
under high shear conditions
C. bubbles tend to move too quickly
through the bulk liquid
D. the cells clog up the surface of the bubble

172.Surface renewal theory predicts that the

mass transfer coefficient is
A. directly proportional to the square root of
the molecular diffusivity
B. inversely proportional to the square
 BIOCHEMISTRY

C. directly proportional to the cube root of the 180.Lagoons may be characterized as

molecular diffusivity A. anaerobic C. aerated
D. indirectly proportional to the cube root of the B. facultative D. all of these
molecular diffusivity

173.A cylindrical reactor fitted with Rushton Turbine

has a liquid volume of 100,000 litres. It has an
aspect ratio (the ratio of the channel height to
the width) of 2:1. The diameter of the impeller
should be approximately:
A. 1.3 m C. 5.3 m
B. 3.3 m D. 7.3 m

174.What is the effect of the concentration of

dissolved salts and sugars on the oxygen transfer
rate?
A. The saturation concentration of oxygen in the
medium decreases with the concentration of
dissolved salts and sugars, leading to a lower
oxygen transfer rate
B. The KLa of the medium decreases with the
concentration of dissolved salts and sugars,
leading to a lower oxygen transfer rate T
C. he KLa of the medium increases with the
concentration of dissolved salts and sugars,
leading to a lower oxygen transfer rate
D. None of the above

175.Filamentous fungal cells are more shear

sensitive than bacterial cells because of
A. the presence of citin in cell walls of
filamentous fungi
B. larger in size than bacterial cells and
therefore are more susceptible to shear
forces
C. fungal cells are much larger than bacterial
cells
D. all of the above

176.A liquid is flowing at 11,400 l.h-1 along a

pipeline having 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 in the
A. laminar phase C. turbulent phase
B. transient phase D. any of the phase

177.For laminar flow of Newtonian fluid through a

smooth round pipe, the ratio of average fluid
velocity to the maximum velocity is
A. 0.5 C. 0.87
B. 0.75 D. 0.37

178.Both temporary and permanent hardness of

water can be removed on boiling water with
A. calcium hydroxide C. calcium oxide
B. sodium carbonate D. calcium carbonate

179.Inhibitors are used along with sanitizer

A. to improve their action
B. to prevent corrosion
C. both (a) and (b)
D. none of these
 BIOCHEMISTRY

substrate is equal to the monod constant

181.If a reaction occurs in the absence of inhibitor
with rate ν0 and in the presence of inhibitor 189.The region of an airlift bioreactor in which the
with rate νi, the degree of inhibition is defined liquid travels in a downward direction is called
as the
A. (ν0 - νi)/ν0 C. (ν0νi)/ν0 A. downcomer C. air riser
B. (ν0 + νi)/ν0 D. (ν0-νi)/νi B. disengagement zone D. flotsam

182.Various techniques are available for

determining the effective diffusivity of solute
in gel. Thin disk method uses
A. a diffusion cell with two compartments
divided by a thin gel
B. a diffusion cell with two compartments
C. a diffusion cell with two compartments
plus by a thin gel
D. a diffusion cell with two compartments
multiply by a thin gel

183.The enzyme β-galactosidase is also known as

A. lactase C. both (a) and (b)
B. EC3.2.1.23 D. isomerase

184.The main reason for production of antibiotics

in fed batch reactors is
A. the presence of precursors is often toxic to
the cells
B. higher yields when cells enter the stationary
phase
C. higher yields when cell growth slows
D. all of the above

185.Which of the following is used to

calculate mass of substrate in the reactor?
A. Flow rate x substrate concentration in the
reactor
B. Volume of reactor x substrate concentration
in reactor
C. Flow rate x mass of reactor
D. Volume of reactor x Flow rate

186.The fastest route of NADH reoxidation is

A. aerobic respiration C. fermentation
B. anaerobic respiration D. decomposition

187.Which of the following organisms will

continue their metabolism at high substrate
concentrations?
A. Pseudomonas aeruginosa
B. Saccharomyces cerevisiae
C. Bacillus subtilis
D. Escherichia coli

188.During the exponential phase the

maximum specific growth rate equals
specific growth rate as
A. concentration of the growth limiting
substrate is much less than the monod
constant
B. concentration of growth limiting substrate
is much greater than the monod constant
C. specific growth rate increases exponentially
D. concentration of the growth limiting
 BIOCHEMISTRY

diffusion respectively)
190.The function of the disengagement zone in A. 1 - ηimpηintηdif
an airlift fermenter is to B. 1 - (1 - ηimp)(1 - ηint)(1 - ηdif)
A. prevent CO2 rich bubbles from entering
the downcomer
B. reduce the velocity of the bubbles r
C. educe liquid loss as aerosols
D. all of the above

191.An open system in which the growth rate is

maintained by adding a nutrient (present in
limiting quantities) at the same rate as that
medium containing microorganisms is removed
is called
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
-1 -1
B. 3 mg*L *s 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
 BIOCHEMISTRY

C. 1 - ( ηimpηint/ηdif)
D. None of the above

199.The maximum desirable limit (BIS of

mercury in the drinking water is
A. 0.05 mg/L C. 0.1 mg/L
B. 0.9 mg/L D. 0.001 mg/L

200.Conventional tertiary treatment is

A. chemical coagulation and flocculation
B. filtration
C. sedimentation
D. none of these