1
Q
A competitive inhibitor of an enzyme is usually
a. a highly reactive compound
b. a metal ion such as Hg2+ or Pb2+
c. structurally similar to the substrate.
d. water insoluble
A
c. structurally similar to the substrate.
2
Q
Linear inhibition is sometimes called as
a. complete inhibition
b. incomplete inhibition
c. partial inhibition
d. mixed inhibition
A
a. complete inhibition
3
Q
The types of inhibition pattern based on Michaelis Menten equation are
a. competitive
b. non-competitive
c. uncompetitive
a. induced fit
d. all of the above
A
d. all of the above
4
Q
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-intercep
c. it can change the x-intercep
d. all of these
A
b. it can change the y-intercep
5
Q
In competitive inhibition a factor is obtained from the measurement of
a. Vmax
b. KM
c. Y-intercept in Lineweaver-Burk Plot
d. None of these
A
b. KM
6
Q
Which of these proteases is not a cysteine active site protease?
a. Calpain
b. Cathepsin D
c. Papain
d. None of the above
A
b. Cathepsin D
7
Q
Given an enzyme with a Km = 10m M and Vmax = 100m mol/min. If [S] = 100m M, which of the following will be true?
a. A 10-fold increase in Vmax would increase velocity 10-fold y
b. A 10-fold decrease in Km would increase velocity
c. Both (a) and (b)
d. A 10-fold increase in Vmax would decrease velocity 20-fold
A
a. A 10-fold increase in Vmax would increase velocity 10-fold y
8
Q
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
b. transition
c. fit and fine
d. Pasteur
A
a. induced fit
9
Q
The active site of an enzyme remains
a. at the center of globular proteins
b. rigid and does not change shape
c. complementary to the rest of the molecule
d. none of the above
A
d. none of the above
10
Q
Which category of enzymes belongs to class two in the international classification?
a. Hydrolases
b. Ligases
c. Transferases
d. Isomcrasc
A
c. Transferases
11
Q
The Woolf-Augusteinsson-Hofstee plot of v versus v/[S] and the Eadie Scatchard plot of v/[S] versus v do not involve reciprocals of v therefore are considered to be more reliable when the error in v is
a. non-significant
b. significant
c. nothing to do with the reliability
d. non-significant in selected cases
A
b. significant
12
Q
The relationship between Keq, Km and Vmax is known as
a. Haldane equation
b. Michaelis Menten equation
c. Numerical solution approach
d. Gibbs-Helmholtz equation
A
a. Haldane equation
13
Q
The reciprocal equation for non-competitive inhibition can be arranged to the equation for the
a. Dixon plot
b. Woolf-Augusteinsson-Hofstee plot
c. Eadie-Scatchard plot
d. Hanes-Woolf plot
A
a. Dixon plot
14
Q
Which of the following statements is true for enzymatically catalyzed reaction?
a. The activation energy of the reaction is lowered so that a larger proportion of the substrate qualifies to overcome it
b. Additional substrate molecules are energized to overcome the activation energy of the reaction
c. The activation energy of the reaction is increased, thus decreasing the likelihood that any substrate molecules will overcome it
d. The activation energy of the reaction is lowered so that fewer substrate molecules can overcome it
A
a. The activation energy of the reaction is lowered so that a larger proportion of the substrate qualifies to overcome it
15
Q
Which of the following common drugs is not a specific enzyme inhibitor?
a. Iodine
b. Methotrexate
c. Sulfanilamide
d. Penicillin
A
a. Iodine
16
Q
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
A
c. It changes the x-intercept
17
Q
Which of the following statements is not true?
a. Enzymes are proteins that bind to specific substrates and increase the velocity of reactions involving those substrates
b. Enzymes function by overcoming the activation energy barrier of a reaction
c. Enzymes make thermodynamically favorable reactions to proceed; they cannot make unfavorable reactions to occur
d. Enzymes only function when they are in intact cells
A
d. Enzymes only function when they are in intact cells
18
Q
An enzyme and a reactant molecule maintain relationship as
a. a temporary association
b. an association stabilized by a covalent bond
c. one in which the enzyme is changed permanently
d. non complementary binding
A
a. a temporary association
19
Q
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 2 x 10-3M. The value of k in minute is
a. 0.115
b. 0.42
c. 0.093
d. 6.693
A
a. 0.115
20
Q
The plot commonly used for determining the value of Vmax is
a. Lineweaver Burk plot
b. Langmuir plot
c. Eadie Hofstee plot
d. all of these
A
d. all of these
21
Q
Quasi steady state is also known as
a. Michaelis Menten approach
b. Briggs-Haldane approach
c. Pseudo steady state
d. all of the above
A
c. Pseudo steady state
22
Q
Which of these enzymes contains a Zinc (Zn) ion?
a. Carboxypeptidase A
b. Phosphorylase B kinase
c. Tyrosine hydroxylase
d. Phosphodiesterase
A
a. Carboxypeptidase A
23
Q
A noncompetitive inhibitor of an enzyme-catalyzed reaction
a. increases KM and increases Vmax
b. increases KM and reduces Vmax
c. reduces KM and increases Vmax
d. reduces KM and reduces Vmax
A
b. increases KM and reduces Vmax
24
Q
An allosteric inhibitor of an enzyme usually
a. participates in feedback regulation
b. denatures the enzyme
c. is a hydrophobic compound
d. causes the enzyme to work faste
A
a. participates in feedback regulation
25
A classical uncompetitive inhibitor is a compound that binds
a. reversibly to the enzyme substrate complex yielding an inactive ESI complex
b. irreversibly to the enzyme substrate complex yielding an inactive ESI complex
c. reversibly to the enzyme substrate complex yielding an active ESI complex
d. irreversibly to the enzyme substrate complex yielding an active ESI complex
a. reversibly to the enzyme substrate complex yielding an inactive ESI complex
26
During the log phase cell numbers increase exponentially
a. because cells produce enzymes
b. because cells do not have cell membranes
c. because cells are auto catalysts
d. because the rate of cell division increases exponentially
c. because cells are auto catalysts
27
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 determine
a. Hill plot
28
The ratio of the amount of a protein present in a sample, which is used as a measure of purification, is known as
a. specific activity
b. relative activity
c. purity ratio
d. all of these
a. specific activity
29
If a reaction occurs in the absence of inhibitor with rate ν0 and in the presence of inhibitor with rate νi, the degree of inhibition is defined as
a. (ν0 - νi)/ν0
b. (ν0 + νi)/ν0
c. (ν0νi)/ν0
d. (ν0-νi)/νi
a. (ν0 - νi)/ν0
30
The rate equation in competitive inhibition based on Michaelis Menten equation is given by
a. rmaxS/(Km(1+I/Ki) +S))
b. rmaxE/(Km(1+I/Ki) +S))
c. rmaxI/(Km(1+I/Ki) +S))
d. rmaxS/(Km(1+I/Ki))n
a. rmaxS/(Km(1+I/Ki) +S))
31
Classical noncompetitive inhibition is obtained only under
a. slow equilibrium conditions
b. moderate equilibrium conditions
c. rapid equilibrium conditions reactions
d. non-equilibrium conditions
c. rapid equilibrium conditions reactions
32
In the steady state the material balance equation for any component of a system is
a. rate of addition + rate of removal - rate of formation = 0
b. rate of addition - rate of removal + rate of formation = 0
c. rate of addition + rate of removal + rate of formation = 0
d. none of the above
b. rate of addition - rate of removal + rate of formation = 0
33
For an enzyme that displays Michaelis-Menten kinetics, the reaction velocity (as a fraction of Vmax) observed at [S] = 2 KM will be
a. 0.09
b. 0.33
c. 0.66
d. 0.91
c. 0.66
34
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
a. competitive inhibition is greater than uncompetitive inhibition
35
An enzyme has a Km of 4.7 x 10-5M. If the Vmax of the preparation is 22m moles liter-1 min-1, what velocity would be observed in the presence of 2.0 x 10-4M substrate and 5.0 x 10-5M of a competitive inhibitor?
a. 13.54μ moles liter-1min-1
b. 6.68μ moles liter-1min-1
c. 7.57μ moles liter-1min-1
d. 17.8μ moles liter-1min-1
a. 13.54μ moles liter-1min-1
36
Which of the following statement(s) regarding enzymes, is/are false?
a. Enzymes are always proteins that function as catalysts
b. Enzymes provide activation energy for reactions
c. Enzyme activity can be regulated
d. Enzymes may be used many times for a specific reaction
b. Enzymes provide activation energy for reactions
37
The slope of Lineweaver Burk plot for Michaelis Menten equation is
a. Vmax/Km
b. Km/Vmax
c. 1/Km
d. Km•Vmax
b. Km/Vmax
38
The initial velocity, Vo, of an enzyme catalyzed reaction reaches Vmax as
a. [S] = KM
b. [S] = 10 * KM
c. 1/[S] = 1/KM
d. 1/[S] → 0
d. 1/[S] → 0
39
The usual method(s) to solve rate equation of simple enzyme kinetics is/are
a. Michaelis Menten approach
b. Briggs-Haldane approach
c. Numerical solution approach
d. all of these
d. all of these
40
Michaelis Menten equation can also be written as
a. (-Cs)/r = (Cs/rmax)+(Km/rmax)
b. 1/r = (1/rmax)+(Km/(rmax.Cs))
c. r = rmax-(Km.r/Cs)
d. All of these
d. All of these
41
Which of the following step is assumed to be the 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
b. The product releasing step
42
When substrate [S] = KM (Michaelis-Menten constant), the velocity of an enzyme catalyzed reaction is about
a. 0.1 * Vmax
b. 0.2 * Vmax
c. 0.5 * Vmax
d. 0.9 * Vmax
c. 0.5 * Vmax
43
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
b. no effect on substrate binding and vice versa
44
The active site of an enzyme differs from an antibody-antigen binding site in that the enzyme active site
a. contains modified amino acids
b. catalyzes a chemical reaction
c. is complementary to a specific ligand
d. contains amino acids without side chains
b. catalyzes a chemical reaction
45
Enzymes are basically
a. Proteins
b. Vitamins
c. Fat
d. Carbohydrates
a. Proteins
46
Which of the following refers to pseudo steady state?
a. d(CE)/dt = 0
b. d(Cp)/dt = 0
c. d(CES)/dt = 0
d. d(Cs)/dt = d(CES)/dt
c. d(CES)/dt = 0
47
Most enzymes work by
a. increasing energy of activation
b. decreasing energy of activation
c. not affecting energy of activation
d. none of the above
b. decreasing energy of activation
48
Which category of enzymes belongs to class 5 in the international classification?
a. Hydrolases
b. Isomerases
c. Oxido-reductases
d. Cyclase
b. Isomerases
49
Lock and key theory is based on the compatibility of
a. enzyme and substrate
b. enzyme and product
c. enzyme and enzyme substrate complex
d. enzyme substrate complex and produc
a. enzyme and substrate
50
When an enzyme is functioning at Vmax, the rate of the reaction is limited by
a. the number of collisions between enzyme and substrate
b. the number of substrate molecules in the reaction
c. the concentration of the substrate
d. the rate at which the enzyme can convert versa
d. the rate at which the enzyme can convert versa
51
When [S] = 0.1 *KM, the velocity of an enzyme catalyzed reaction is about:
a. 0.1 * Vmax
b. 0.3 * Vmax
c. 0.5 * Vmax
d. 0.7 * Vmax
a. 0.1 * Vmax
52
Juice clarification extraction is facilitated by using
a. Cellulases
b. Amylase
c. Inulinase
d. Lactase
a. Cellulases
53
Lysozyme is naturally present in
a. egg white
b. bacteria
c. tears & milk
d. all of these
d. all of these
54
Trichoderma β-glucanase is reported
a. to stabilize mashing
b. to convert taste fractions of dextrins to
fermentable sugars in beer
c. to convert starch to dextrin
d. all of the above
a. to stabilize mashing
55
The bitter taste of the high protein materials is reduced by using
a. Invertase
b. Dectinase
c. Protease
d. none of these
c. Protease
56
Sulphydryl oxidase is used for
a. Discoloration
b. clarification of images
c. UHT milk off flavor removal
d. all of these
c. UHT milk off flavor removal
57
α-amylase is an endo enzyme which requires
a. Ca
b. Cu
c. Mn
d. None of these
a. Ca
58
Liquefaction of starch to dextrin is carried out by
a. α-amylase
b. cellulase
c. pectinase
d. all of these
a. α-amylase
59
Milk digestibility is improved by using
a. RNase
b. Lactase
c. β-amylase
d. none of these
b. Lactase
60
Which of the following mainly serve to convert starch into high fructose corn syrup (HFCS)?
a. α-amylase
b. Gluco-isomerase
c. Gluco-amylase
d. all of these
d. all of these
61
Lysozyme
a. catalyses hydrolysis of β-1-4 linkages between N-acetyl muranic acid and N-acetyl glucosamine in peptideoglycan
b. catalyses hydrolysis of α-1-4 linkages between N-acetyl muranic acid and N-
acetyl glucosamine in peptideoglycan
c. catalyses hydrolysis of α-1-4 linkages between N-diacetyl muranic acid and N-diacetyl glucosamine in peptideoglycan
d. all of the above
a. catalyses hydrolysis of β-1-4 linkages between N-acetyl muranic acid and N-acetyl glucosamine in peptideoglycan
62
Hersperidinase is used for
a. juice clarification
b. juice debittering
c. off flavour reduction
d. RNA reduction in fish
a. juice clarification
63
Which of the following metallic ion is there in ascorbic acid oxidase?
a. Mg
b. Fe
c. Cu
d. Mn
c. Cu
64
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
b. Glucose oxidase-catalase
65
Citrus juice debittering can be carried out using
a. Limoninase
b. Inulinase
c. Anthocyanase
d. None of these
a. Limoninase
66
Which of the following enzyme is responsible for causing vitamin B deficiency disease beriberi?
a. Ascorbic acid oxidase
b. Thiaminase
c. Lipoxygenase
d. None of these
b. Thiaminase
67
Soya off flavour removal may be achieved using
a. di acetyl reductase
b. β- amylase
c. aldehyde oxidase
d. protease
c. aldehyde oxidase
68
The reduction in off flavour of beer is practicedmthrough
a. Hersperidinase
b. Rnase
c. Invertase
d. diacetyl reductase
d. diacetyl reductase
69
Discoloration can be achieved by using
a. sulphloydryl oxidase
b. proteases
c. anthocyanase
d. all of these
c. anthocyanase
70
The prosthetic group present in phenolasenenzyme is
a. Mg
b. Cu
c. Ca
d. Fe
b. Cu
71
Enzymes degrade, alter or synthesize a food component through
a. oxidation/reduction/isomerization
b. hydrolysis/synthesis
c. group transfer
d. all of the above
d. all of the above
72
Chymosin hydrolyses the bond between
a. Alanine and glycine
b. Phenyl alanine and methionine
c. Glutamic acid and alanine
d. Alanine and phenyl alanine
b. Phenyl alanine and methionine
73
Stationary phase is described as
a. no further increase in the cell population after a maximum value
b. deceleration of growth and division rate after the growth rate reaches a maximum
c. acceleration of growth and division rate after the growth rate reaches a maximum
d. deceleration of growth and division rate after the growth rate reaches a minimum
a. no further increase in the cell population after a maximum value
74
In the accelerated phase, cell starts to
a. increase and the division rate increases to reach a maximum
b. decrease and the division rate increases to reach a maximum
c. increase and the division rate decreases to reach a maximum
d. increase and the division rate increases to reach a minimum
a. increase and the division rate increases to reach a maximum
75
The Monod model predicts that the specific growth rate
a. will increase with the concentration of the growth limiting substrate until it reaches a maximum value
b. will decrease with the concentration of the growth limiting substrate
c. will increase with the concentration of the growth limiting substrate
d. does not depend on growth limiting substrate
a. will increase with the concentration of the growth limiting substrate until it reaches a maximum value
76
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
c. both acid and alcohol
77
The phenomenon in which substrates are used in a sequential manner is known as
a. trans-substrate genesis
b. dialism
c. diauxie
d. multiplicity
c. diauxie
78
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
b. VR/F
c. μ/F
d. F/μ
a. F/VR
79
Diauxie is
a. growth factors
b. microbiological die off
c. the simultaneous uptake of nutrients
d. the stagewise uptake of nutrients
d. the stagewise uptake of nutrients
80
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 micro-organism is removed is called
a. Manostat
b. Chemostat
c. Turbidostat
d. Culturostat
b. Chemostat
81
In the death phase
a. nutrients available for the cells are deplete and begin to die
b. the number of viable cells will increase
c. nutrients available for cells are replenished and start to multiply
d. none of the above
a. nutrients available for the cells are deplete and begin to die
82
The maximum specific growth rate of an organism depends on
a. medium composition
b. temperature
c. pH
d. All of these
d. All of these
83
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
c. The Monod model was derived from an analysis of the mechanism of microbial growth
84
Bubble column reactor has
a. large height to diameter ratio
b. small height to diameter ratio
c. large diameter to height ratio
d. small diameter to height ratio
a. large height to diameter ratio
85
An open system in which the growth rate is maintained by the removal and addition of media at such a rate as to maintain a constant cell density is called a
a. Manostat
b. Chemostat
c. Turbidostat
d. Culturostat
c. Turbidostat
86
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
b. dilution rate is higher than the maximum specific growth rate
87
Fermenter should be filled with medium upto
a. 65-70%
b. 70-75%
c. 75-80%
d. 80-85%
c. 75-80%
88
Bacterial growth curve is obtained by plotting
a. number of cells versus time
b. number of spores versus time
c. log of number of cells versus time
d. log of number of cells survived versus time
d. log of number of cells survived versus time
89
When intracellular enzymes of whole cells are to be used in a bio-conversion process, it is often necessary to____________the cells.
a. Permeabilize
b. Lyophilize
c. heat-kill
d. denature
a. Permeabilize
90
Heat transfer rates (per unit volume) will be lowest in
a. Stirred tank bioreactor with biomass recycle
b. Continuous air lift bioreactor
c. Continuous packed bed reactor
d. Continuous fluidized bed bioreacto
c. Continuous packed bed reactor
91
The Monod Model relates
a. substrate utilized with the biomass consumption
b. specific growth rate to the substrate availability
c. yield with the biomass utilization
d. the biomass concentration with specific growth rate
b. specific growth rate to the substrate availability
92
The height to diameter ratio (H/D) for the column fermenters is
a. <3
b. >3
c. <1.5
d. >1.5
b. >3
93
The region of an airlift bioreactor in which the liquid travels in a downward direction is called the
a. Downcomer
b. disengagement zone
c. air riser
d. flotsam
a. Downcomer
94
Population doubling time, td can be expressed as (where μ is the specific growth rate.)
a. log2/μ
b. ln2/μ
c. μ/ln2
d. μ/log2
b. ln2/μ
95
A higher Ks value of Monod's equation means
a. greater affinities to substrate
b. lower affinities to substrate
c. unaffected with the substrate bonding
d. lower dissociation constant value
a. greater affinities to substrate
96
The increased air flow rate in bubble column fermenter can cause excessive foaming and high retention of air bubbles in the column which
a. decreases the productivity of the fermenter
b. increases the productivity of the fermenter
c. modestly increases the productivity of the fermenter
d. does not affect on the productivity
a. decreases the productivity of the fermenter
97
In an airlift bioreactor, the spent gases released from the liquid are called
a. Downcomer
b. disengagement zone
c. air riser
d. flotsam
b. disengagement zone
98
The contents in jet loop reactor are mixed through
a. compressed air
b. a mechanical agitator
c. external pumping
d. any of these
c. external pumping
99
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
c. the rate of individual cells division or increase in their biomass
100
The number of baffles in a standard stirred tank bioreactor is
a. 8
b. 6
c. 4
d. 2
c. 4
101
In the stationary phase
a. growth is proportional to death
b. growth rate is equal to death rate
c. growth rate is lesser than death rate
d. no co-relation exist between death rate and growth rate
b. growth rate is equal to death rate
102
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
d. All of the above
103
Biomass concentrations during fermentation is
a. diluting the samples to optical density less than 0.3
b. monitored by controlling the changes in biomass concentrations
c. considering that optical density is proportional to the surface area of the biomass in the sample
d. all of the above
d. all of the above
104
Chemostats work on the principle of
a. maintaining constant volume of culture medium
b. maintaining continuous flow of nutrients
c. maintaining uniform nutrients concentration
b. disengagement zone
c. maintaining uniform nutrients concentration
105
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 substrate is equal to the Monod constan
b. concentration of growth limiting substrate is much greater than the Monod constant
106
A functional relationship between the specific growth rate and essential compounds concentration was proposed by Monod in
a. 1958
b. 1946
c. 1942
d. 1950
c. 1942
107
The optical density sometimes drops during the lag phase because
a. cells tend to grow without dividing leading to a decrease in the surface area to volume ratio
b. of fast cell growth causing them to fill up with DNA
c. cells swell up with water
d. cells swell up with RNA
a. cells tend to grow without dividing leading to a decrease in the surface area to volume ratio
108
The application of just in time (JIT) manufacturing techniques in biotechnology is important because
a. raw materials used in biotechnology are biodegradable
b. the products of biotechnology are biodegradable
c. it is a very competitive business
d. all of the above
d. all of the above
109
Residence time distribution (RTD) of a reactor is independent of
a. micro mixing
b. volume of reactor
c. height of the reactor
d. width of the reacto
a. micro mixing
110
A culture in a closed vessel to which no additional medium is added and from which no waste products are removed is called a __________ culture.
a. Continuous
b. Batch
c. fed-batch
d. semi continuous
b. Batch
111
If the specific growth rate, μ. is constant with time during the exponential growth period, the equation correlating bacterial number density (Cn), cell number concentration with respect to time can be expressed as
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)
a. Cn= Cn0 exp [μ (t - t0)]
112
The diameter of the baffles in a standard stirred tank bioreactor ranges from
a. 1/10th - 1/12th of the tank diameter
b. 1/3rd - 1/4th of the tank diameter
c. 1/15th - 1/20th of the tank diameter
d. 1/20th - 1/25th of the tank diamete
a. 1/10th - 1/12th of the tank diameter
113
Lag phase occurs mainly due to
a. acclimatization with new environment and substrate
b. higher growth temperature
c. substrate disliking
d. variation in substrate concentration
c. substrate disliking
114
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
c. changes during the fermentation
115
Turbidostat is recommended when continuous fermentation needs to be carried out at
a. high dilution rates near the washout point
b. low dilution rates near the washout point
c. moderate dilution rates near the washout point
d. any intensity of dilution rates near the washout point
a. high dilution rates near the washout point
116
The specific growth rate is affected by
a. substrate concentration
b. product concentration
c. oxygen supply
d. all of these
d. all of these
117
The main function(s) of a draft tube in an air lift fermenter is/are to
a. increase the solubility of oxygen
b. distribute shear forces throughout the reactor and minimize bubble coalescence
c. concentrate shear forces around the sparger
d. concentrate shear forces near the disengagement zone
b. distribute shear forces throughout the reactor and minimize bubble coalescence
118
Which of the following is incorrect?
a. The mechanical agitation and aeration are effective for suspension of cells
b. The mechanical agitation and aeration are effective for mixing the medium
c. STF can't be used for high viscosity medium
d. The mechanical agitation and aeration are effective for oxygenation
c. STF can't be used for high viscosity medium
119
The contents in bubble column and air lift reactor are mixed through
a. compressed air
b. a mechanical internal moving part
c. external pumping
d. any of these
a. compressed air
120
During the lag phase
a. cells just start growing
b. cells synthesize new proteins and membrane components
c. cells produce antibiotics to kill competing organisms
d. cells simply grow slowly
b. cells synthesize new proteins and membrane components
121
Concentration of the growth limiting substrate means
a. trace elements concentration
b. the concentration of the substrate that controls the growth rate of the cells
c. sugar concentration in the fermentation medium
d. dissolved oxygen concentration
b. the concentration of the substrate that controls the growth rate of the cells
122
Tower fermenters are used for
a. continuous penicillin production
b. continuous beer production
c. production of enzymes
d. batch production of beer
b. continuous beer production
123
In wastewater treatment, which bioreactor is generally used?
a. Plug flow reactor
b. Trickle bed reactor
c. Tower fermenter
d. CST
b. Trickle bed reactor
124
The contents in stirred tank rector are mixed through
a. compressed air
b. a mechanical agitator
c. external pumping
d. any of
b. a mechanical agitator
125
The height to diameter ratio (H/D) for the tank fermenters is
a. < 3
b. > 3
c. < 1.5
d. > 1.5
a. < 3
126
The relatively large volume (10 to 40% of total fermenter volume) of the seed culture is employed to
a. increase the overall fermentation time
b. increase the overall yield of biomass
c. decrease the overall fermentation time
d. decrease the overall yield of product
c. decrease the overall fermentation time
127
In an airlift bioreactor, the air sparging region is called
a. Downcomer
b. disengagement zone
c. air riser
d. none of these
c. air riser
128
The air riser is located on the outside of the draft tube for the large-scale airlift bioreactors because of
a. higher oxygen transfer rates
b. a small sparge ring
c. better heat transfer efficiencies
d. all of these
c. better heat transfer efficiencies
129
At the end of the lag phase, when growth begins, the division rate increases gradually and reaches a maximum value in the exponential growth period. This transitional period is commonly called the accelerated growth phase and is often included as a part of the
a. lag phase
b. stationary phase
c. death phase
d. exponential growth phase
a. lag phase
130
Which of the following(s) is/are considered the limitations of the exponential growth model?
a. Only predicts that cells grow exponentially during the log phase
b. It does not consider factors that causes cells growth to stop or slow
c. Predicts cell growth at a linear rate
d. All of the above
b. It does not consider factors that causes cells growth to stop or slow
131
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
a. Disengagement zone, air riser, downcomer
132
The viscosity of liquid was classified as both dilatant and rheopectic, which means that the viscosity
a. increased with stirring speed but decreased with mixing time
b. increased with stirring speed and increased with mixing time
c. decreased with stirring speed but increased with mixing time
d. decreased with stirring speed and decreased with mixing time
b. increased with stirring speed and increased with mixing time
133
A fluid in which the viscosity decreases with increasing stirrer speed and mixing time, can be represented as
a. Newtonian fluid
b. pseudoplastic, thixotropic fluid
c. dilatant, rheopectic fluid
d. dilatant, pseudoplastic fluid
b. pseudoplastic, thixotropic fluid
134
The viscosity of water at STP is approximately
a. 0.005 kg-m-1-s-1
b. 0.001 kg-m-1-s-1
c. 0.003 kg-m-2-s-1
d. 0.1 g-cm-1-s-1
b. 0.001 kg-m-1-s-1
135
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
a. silicone tubing or gas permeable membranes to facilitate gas transfer
136
If the viscosity of a fluid decreases with increasing stirrer speed, then the nature of the fluid is
a. Newtonian
b. Pseudoplastic
c. Dilatant
d. Thixotropic
b. Pseudoplastic
137
A pseudoplastic 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 increasing stirrer speed
d. decreases with increasing stirrer speed
d. decreases with increasing stirrer speed
138
A viscoelastic 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 increasing stirrer speed
d. decreases with increasing stirrer speed
b. changes during mixing but returns to its original state after mixing
139
Mixing in stirred tank reactors can
a. be described as either laminar, transient or turbulent
b. achieve turbulent conditions by increasing the stirrer speed
c. induce laminar flow conditions by the addition of baffles
d. all of the above
a. be described as either laminar, transient or turbulent
140
In animal cell bioreactor, bubble damage can be minimized by
a. the addition of a shear protectorant
b. using a bubble free oxygen delivery system
c. headspace aeration
d. all of the above
d. all of the above
141
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
b. Rheopectic
c. Viscoelastic
d. Thixotropic
c. Viscoelastic
142
In sparged mammalian cell bioreactors, the cell damage is caused because of
a. shear stress arising during mixing of the cell culture fluid
b. shear stresses arising from the breakup of bubbles at the liquid surface
c. shear stresses between bubbles in foam at the liquid surface
d. all of the above
a. shear stress arising during mixing of the cell culture fluid
143
The SI unit for viscosity is
a. kg-m-1-s-1
b. kg-m-2-s-2
c. kg-m-3-s-1
d. kg-m-1-s-2
a. kg-m-1-s-1
144
The viscous nature of a non-Newtonian fluid
a. remains constant with time and power input
b. changes with the level of power input and/or the length of time during which the fluid is mixed
c. is similar to that of a perfect gas
d. is similar to that of water
b. changes with the level of power input and/or the length of time during which the fluid is mixed
145
Which of the following compound, if added to a solution will lead to the greatest increase in viscosity?
a. A globular protein
b. Glucose
c. A long chain protein such as albumin
d. Water
c. A long chain protein such as albumin
146
A Brookfield viscometer measures viscosity by determining
a. the shear stress
b. the shear rate
c. the shear stress and shear rate
d. the torque required to move an impeller at a set speed
d. the torque required to move an impeller at a set speed
147
Which of the following factors will affect the sensitivity of animal cells to shear conditions?
a. Cell size
b. Availability of nutrients in the medium
c. The presence of shear protectorants in the medium
d. All of the above
d. All of the above
148
The best described action of Pluronic F68 (non-ionic detergent) in a cell culture medium is that, it
a. acts on the surface properties of the cells and the culture medium
b. provides nutrients for the cells
c. acts as a flocculant
d. acts as a coagulant
a. acts on the surface properties of the cells and the culture medium
149
Water is a
a. Newtonian fluid
b. Pseudoplastic
c. Dilatant
d. Rheopectic
a. Newtonian fluid
150
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
d. All of these
151
A liquid is flowing at 11,400 I.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
b. transient phase
c. turbulent phase
d. any of the phase
c. turbulent phase
(Re = 126.67???)
152
The viscosity of a fluid increases with the length of time that it is being mixed. This fluid would be best described as being
a. Newtonian
b. Rheopectic
c. Viscoelastic
d. Thixotropic
b. Rheopectic
153
Which of the following can act as a shear protectorant?
a. Serum
b. Silicone oil
c. Glucose
d. Glutamic acid
a. Serum
154
The viscosity of a fluid increases with increasing stirrer speed. This fluid would be best described as being
a. Newtonian
b. Pseudoplastic
c. Dilatant
d. Thixotropic
c. Dilatant
155
A dilatant 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 increasing stirrer speed
d. decreases with increasing stirrer speed
c. increases with increasing stirrer speed
156
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
c. increases with mixing time
157
A fluid in which the viscosity increases with increasing stirrer speed and mixing time can be called as
a. Newtonian fluid
b. pseudoplastic, thixotropic fluid
c. dilatant, rheopectic fluid
d. dilatant pseudoplastic fluid
c. dilatant, rheopectic fluid
158
The medium will have the highest viscosity (considering that the cells do not secrete gums) with the presence of
a. single celled bacteria
b. filamentous fungi that form pellets
c. filamentous fungi that grow as long poorly branched chains
d. yeast
c. filamentous fungi that grow as long poorly branched chains
159
A Newtonian 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 increasing stirrer speed
d. decreases with increasing stirrer speed
a. is constant regardless of the stirrer speed or mixing time
160
Which pattern of mixing is preferred in stirred tank reactors during the culture of aerobic microorganisms?
a. Laminar flow
b. Transient flow
c. Turbulent flow
d. All of these
c. Turbulent flow
161
Animal cell cultures do not have much effect on shear forces because
a. the cell size is generally smaller than the critical eddy size at which shear will have an effect
b. cells are larger than the critical eddy size at which shear will have an effect
c. animal cells have cell walls
d. animal cells have cell membranes
a. the cell size is generally smaller than the critical eddy size at which shear will have an effect
162
Animal cell cultures do not have much effect on shear forces because
a. the cell size is generally smaller than the critical eddy size at which shear will have an effect
b. cells are larger than the critical eddy size at which shear will have an effect
c. animal cells have cell walls
d. animal cells have cell membranes
d. animal cells have cell membranes
163
The viscosity of the culture fluid is classified as both pseudoplastic and thixotropic which indicates that the viscosity
a. increases with stirring speed but decreases with mixing time
b. increases with stirring speed and increases with mixing time
c. decreases with stirring speed but increases with mixing time
d. decreases with stirring speed and decreases with mixing time
d. decreases with stirring speed and decreases with mixing time
164
Pluronic F68 is added to cell culture media as
a. a nutrient
b. a shear protectorant
c. to increase oxygen transfer rates
d. all of these
b. a shear protectorant
165
A stirred tank reactor containing a fluid with a density of 2.5 g-ml-1 and viscosity of 0.002 kg m-1s-1 is mixed at 120 rpm. If the fluid is mixed with an impeller having diameter 50 cm, then the Reynolds number of the liquid in the reactor
a. 2500
b. 100
c. 1,250,000
d. 1,000,000
c. 1,250,000
(Re = 3926.99???)
166
If the viscosity of a fluid decreases with the length of time that it is being mixed, then this fluid is
a. Newtonian
b. Rheopectic
c. Viscoelastic
d. Thixotropic
d. Thixotropic
167
Which of the following describes the importance of the Kolmogorov eddy size in the biotechnology?
a. The Kolmogorov eddy size is a measure of the smallest eddy size in a liquid
b. When the Kolmogorov eddy size become equivalent or smaller than the cell or
particle diameter, then the cell or particle become susceptible
c .At the Kolmogorov eddy size, much of the energy of the originating eddy will be released
d. All of the above
d. All of the above
168
A thixotropic 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
d. decreases with mixing time
169
Newtonian fluid is one in which the viscosity
a. remains constant with time and power input
b. increases with the level of power input
c. decreases with the level of power inpu
d. drastically increases with the level of power input
a. remains constant with time and power input
170
Reynolds number for laminar flow over a plate should be less than
a. 500 mm
b. 5 x 10-5
c. 5 x 105
d. 5 m
c. 5 x 105
171
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
c. the level of lactate dehydrogenase activity
172
A Brookfield viscometer cannot determine the shear stress because
a. the shear stress is not defined
b. a computer is required
c. the impeller type is given only by numbers
d. all of the above
a. the shear stress is not defined
173
Which of the following is correct?
a. The viscosity of liquids and gases decrease with increasing temperature
b. The viscosity of liquids and gases increase with increasing temperature
c. the viscosity of gases increases with increasing temperature, but decreases in liquids
d. the viscosity of gases decreases with increasing temperature, but decreases in liquids.
c. the viscosity of gases increases with increasing temperature, but decreases in liquids
174
The Komologorov eddy size
a. is constant at all stirrer speeds
b. increases with stirrer speed
c. decreases with stirrer speed
d. becomes zero when the stirrer speed is very low
c. decreases with stirrer speed
175
Pluronic F68 protects mammalian cells from damage stems as it is a/an
a. surface active agent which stabilizes foams
b. surface active agent which destabilizes foams
c. excellent source of vitamins
d. coagulant
a. surface active agent which stabilizes foams
176
Reynolds number for turbulent flow over a plate should be more than
a. 5 x 10-5
b. 106
c. 5 × 105
d. 500
b. 106
177
A system which requires less solvent and produces a more concentrated extract phase, is desired with a
a. large distribution coefficients
b. small distribution coefficients
c. very small distribution coefficients
d. constant distribution coefficients
a. large distribution coefficients
178
Maintenance cost varies from
a. 0-4% of the capital cost
b. 12-16% of the capital cost
c. 4-8% of the capital cost
d. 8-12% of the capital cost
c. 4-8% of the capital cost
179
The optimum wet solid content for the cell suspension for a bead mill is typically somewhere between
a. 5-15% by volume
b. 15-30% by volume
c. 30-60% by volume
d. 60-90% by volume
c. 30-60% by volume
180
Assuming the laminar flow across the filter, the rate of filtration (dVf/dt) can be expressed as a function of pressure drop Dp by the modified D'Arcy's equation as (where A is the area of filtering surface, K is the D'Arcy's filter cake permeability and Lis the thickness of the filter cake)
a. (1/A) dVf/dt = Δp/μ(L/K)
b. dVf/dt = (1/A) Δp/μ(L/K)
c. (1/A) dVf/dt = Δp/μ LK
d. dVf/dt = (1/A) Δp/μ LK
a. (1/A) dVf/dt = Δp/μ(L/K)
181
Filtration leaf test results indicate that the filtration rate of a protein product is 100 dry Ibs/(ft hr). What size production filter would be required to obtain 100 dry Ibs of filter cake/hr?
a. 1.54 ft2
b. 3.08 ft2
c. 65 ft2
d. lbs/ ft2-hr
182
Selectivity can be expressed as
a. ratio of the distribution coefficients in different solute
b. mass fraction of the solute in the extract phase at equilibrium
c. mass fraction of the solute in the raffinate phase
d. ratio of the mass fraction of the solute in the extract phase to the raffinate phase
a. ratio of the distribution coefficients in different solute
183
The disk centrifuge is the type of centrifuge used most often for bio separations due to its
a. continuous operation
b. lesser cost
c. higher speed
d. ease in operation
b. lesser cost
184
The stage wise operation of adsorption is called
a. contact filtration
b. conventional adsorption
c. affinity adsorption
d. ion exchange
a. contact filtration
185
Which of the following is not the physical method for the cells rupturing?
a. Milling
b. Homogenization
c. Ultrasonication
d. Enzymatic digestion
d. Enzymatic digestion
186
Conventional adsorption is a
a. reversible process
b. irreversible process
c. either reversible or irreversible
d. none of these
a. reversible process
187
If the solute passes through membrane freely, the the rejection coefficient (s) is
a. 1
b. 0
c. >1
d. <1
c. >1
188
If the membrane rejects all solute, the rejection coefficient (s) is
a. 1
b. 0
c. >1
d. <1
a. 1
189
In antibiotic manufacturing processes, the fermentation time ranges from
a. 2-3 weeks
b. 1-2 weeks
c. 4-5 weeks
d. 2-4 weeks
c. 4-5 weeks
190
The conventional filtration involves the eparation of large particles generally
a. dp> 5μm
b. dp> 10μm
c. dp> 15μm
d. dp> 20μm
b. dp> 10μm
191
Which of the operation does not come under upstream processing?
a. Media preparation
b. Inoculum development
c. Effluent treatment
d. Storage of raw material
c. Effluent treatment
192
For cost analysis in a fermenter system, the depreciation cost varies from
a. 5-6% of the capital cost
b. 6-7% of the capital cost
c. 6-10% of the capital cost
d. 8-10% of the capital cost
c. 6-10% of the capital cost
193
Micro filtration refers to the separation of suspended material such as bacteria by using a membrane with spore sizes of
a. 0.02 to 10μm
b. 1-10A°
c. 20-30μm
d. 10-200A°
a. 0.02 to 10μm
194
Start up expenses in a fermentation industry varies from
a. 0-5% of the capital cost
b. 10-15% of the capital cost
c. 5-10% of the capital cost
d. 15-20% of the capital cost
c. 5-10% of the capital cost
195
The solvent flux across the membrane can be expressed as (where A is the area, Lp is the membrane permeability, σ is the reflection point, Δp is applied pressure and Δπ is the osmotic pressure)
а. J = Lp(Δp - σΔπ)
b. J/A = Lp(Δp - σΔπ)
c. J = Lp/σΔπ
d. J/A = Lp/Δp
а. J = Lp(Δp - σΔπ)
196
For the extractions operation, the selectivity should be
a. > 1
b. < 1
c. 1
d. Zero
a. > 1
197
The purity of a solute collected between two times t1 and t2 during chromatographic separation can be calculated as
a. amount of solute eluted - amount of impurity eluted
b. amount of solute eluted / amount of impurity eluted
c. amount of solvent eluted + amount of impurity eluted
d. amount of solvent eluted / amount of impurity eluted
b. amount of solute eluted / amount of impurity eluted
198
Chromatography is based on the
a. different rate of movement of the solute in the column
b. separation of one solute from other constituents by being captured on the adsorbent
c. different rate of movement of the solvent in the column
d. any of the above
a. different rate of movement of the solute in the column
199
The correlation often employed to correlate adsorption data for protein is (where Ymax is the maximum amount of solute adsorbed per mass of adsorbent, X is the mass fraction of solute in the diluent phase in solute-free basis. KL is a constant and Y is the equilibrium value of the mass of solute adsorbed per mass of adsorbent)
a. Y = YmaxX/(KL+X)
b. Y= Ymax/(KL+X)
c. Y= YmaxX/KL
d. Y = Ymax- X/ (KL+X)
a. Y = YmaxX/(KL+X)
200
A typical tubular centrifuge has a bowl of 2 to 5 inch in diameter and 9 to 30 inch in height with a maximum rotating speed of
a. 15,000 to 50,000 pm
b. 50,000 to 100,000 pm
c. 100,000 to 150,000 pm
d. 150,000 to 200,000 pm
a. 15,000 to 50,000 pm
201
Water insoluble enzymes can be prepared by using multifunctional agents that are bifunctional in nature and have
a. Low molecular weight
b. High molecular weight
c. High equivalent weight
d. Low reactivity
a. Low molecular weight
202
Functional groups of the nonessential amino acids that are suitable for the immobilization process are
a. Free α-, β- or y carboxyl groups
b. α or β amino groups
c. phenyl, hydroxyl, sulfhydryl, or imidazole groups
d. all of the above
d. all of the above
203
Which medium is used for the production of Penicillin using immobilized cells?
a. 1% peptone medium
b. Glucose medium
c. Yeast extract medium
d. LB broth
b. Glucose medium
204
The immobilized enzyme produced by micro encapsulation technique provides
a. An extremely large surface area
b. Smaller surface area
c. High amount of solvent
d. Relatively smaller surface area
a. An extremely large surface area
205
Which of the following is considered as a disadvantage to the adsorption method of immobilization?
a. It is possible to separate and purify the enzymes while being immobilized.
b. The enzymes are not usually deactivated by adsorption.
c. The adsorption is a reversible process.
d. State of immobilization is very sensitive to solution pH, ionic strength, and temperature.
d. State of immobilization is very sensitive to solution pH, ionic strength, and temperature.
206
During the enzymatic reaction of an immobilized enzyme, the rate of substrate transfer is
a. Equal to that of substrate consumption
b. More than that of substrate consumption
c. Lesser than that of substrate consumption
d. Is nothing to do with the substrate consumption
a. Equal to that of substrate consumption
207
For a steady state condition, the change of substrate concentration (dCs/dt) is
a. Zero
b. 1
c. > 1
d. < 1
a. Zero
208
Damkohler number (NDa) is
a. The ratio of the maximum reaction rate to the maximum mass transfer rate.
b .The ratio of the minimum reaction rate to the maximum mass transfer rate.
c. The ratio of the maximum mass transfer rate to the minimum mass transfer rate.
d. The ratio of the minimum mass transfer rate to the minimum mass transfer rate.
a. The ratio of the maximum reaction rate to the maximum mass transfer rate.
209
For glucose isomerization by immobilized enzyme, the reactor generally used is
a. CSTR
b. Plug flow
c. Packed Bed
d. Fluidized Bed
c. Packed Bed
210
The most commonly employed cross-linked polymer is the
a. Polyacrylamide gel
b. Collagen
c. Celluloses
d. Cation exchange resin
a. Polyacrylamide gel
211
The support material for immobilization of cells of Bacillus subtilis is
a. Ion exchange resins
b. Gelatin
c. Anthracite
d. Agarose and carbodiimide
d. Agarose and carbodiimide
212
The intraparticle mass transfer resistance can affect the rate of enzyme reaction, if enzymes are immobilized by
a. Copolymerization or microencapsulation
b. Cross linking using multifunctional reagents
c. Adsorption
d. All of the above
a. Copolymerization or microencapsulation
213
The covalent attachment of enzyme molecules is via
a. Nonessential amino acids residues to water insoluble, functional supports
b. Essential amino acids residues to water insoluble, functional supports
c. Nonessential amino acids residues to water soluble, functional supports
d. Essential amino acids residues to water soluble, functional supports.
a. Nonessential amino acids residues to water insoluble, functional supports
214
To measure the extent to which the reaction rate is lowered because of resistance to mass transfer, the effectiveness factor of an immobilized enzyme, n 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
c. Actual reaction rate/rate if not slowed by diffusion
215
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.
a. A diffusion cell with two compartments divided by a thin gel.
216
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 increased of particle size.
d. Increase of diffusivity and decreased with the decrease of particle size.
a. Increase of diffusivity and decreased with the increase of particle size.
217
Yield coefficient represents
a. Total biomass or product produced.
b. Conversion efficiency of a substrate into product.
c. Conversion rate of a substrate into biomass or product.
d. Production time of biomass or product.
b. Conversion efficiency of a substrate into product.
218
The lowest biomass yield in a culture of Escherichia coli will be in
a. An aerated batch culture containing an 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.
a. An aerated batch culture containing an initial high concentration of glucose.
219
Mixing in an anaerobic sludge blanket reactor is due to
a. Rapid change in throughout the reactor.
b. Release of gases populations.
c. Swimming of microbes.
d. None of the above
b. Release of gases populations.
220
In batch culture, protogon is produced from peptone during the stationary phase with a yield of 0.4 protogon mg per g of peptone. If it is to be produced in a chemostat at a dilution rate of 0.5 h from a medium containing 10g/L of peptone, then the rate of protogon synthesis would be
a. 0 g/L-h
b. 0.5 g/L-h
c. 1g/L-h
d. 2 g/L-h
a. 0 g/L-h
221
Formation of end product by Lactococcus lactis will become non-growth associated as lactic acid accumulates because
a. Cells will redirect ATP to anabolism.
b. Cells will redirect NAD+ to anabolism.
c. Cells will redirect ATP to facilitate the diffusion of lactic acid and H+ out of the cells.
d. Cells will redirect ATP to the active transport of lactic acid and H+ out of the cells.
d. Cells will redirect ATP to the active transport of lactic acid and H+ out of the cells.
222
Which of the following would not be subjected to the "glucose effect"?
a. Aspergillus fumigatus
b. Saccharomyces cerevisiae
c. Escherichia coli
d. Aspergillus niger
c. Escherichia coli
223
Which of the statement is true for continuous reactor at steady state?
a. The rates of biomass, substrate, and product concentrations are zero.
b. Biomass, substrate, and product concentrations are zero.
c. Biomass, substrate, and product concentrations do not change with time.
d. Biomass, substrate, and product concentrations change with time.
c. Biomass, substrate, and product concentrations do not change with time.
224
A continuous bioreactor in which only the flow rate is used to control the rate of cell or product productivity is called
a. Turbidostat
b. Chemostat
c. Level stat
d. pH
b. Chemostat
225
For organisms growing in a chemostat, the specific growth rate
a. Cannot be determined.
b. Can be determined from the dilution rate.
c. Equals to the maximum specific growth rate of the culture.
d. None of the above.
b. Can be determined from the dilution rate.
226
Saccharomyces cerevisiae is being grown in a chemostat converts glucose to biomass, ethanol, glycerol, and carbon dioxide. At steady state, the concentration of glucose, biomass, ethanol, and glycerol will
a. Decrease with time.
b. Increase with time.
c. Be constant.
d. Change randomly with time.
c. Be constant.
227
In aerobic yeast fermentation for production of citric acid from alkanes using a
fed-batch culture, why alkanes are slowly fed to the yeast?
a. Citric acid is toxic to the cells.
b. Alkanes cause foaming.
c. Fast addition of alkanes will inhibit the cells and reduce oxygen transfer rates.
d. Fast addition of alkanes will cause the cells to grow too quickly.
c. Fast addition of alkanes will inhibit the cells and reduce oxygen transfer rates.
228
A continuous reactor has a dilution rate of 0.5/h. Its residence time would be
a. In(2)/0.5
b. In(2) x 0.5
c. 0.5 h
d. 2 h
d. 2 h
229
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
b. Volume of reactor x substrate concentration in reactor
230
If biomass yields are constant, then the biomass productivity of a culture growth in continuous reactor will
a. Always decrease with dilution rate
b. Increase with dilution rate until washout
c. Remain constant irrespective of the dilution rate
d. Decrease with dilution rate until washout
b. Increase with dilution rate until washout
231
Low dissolved oxygen concentrations leads to
a. Low biomass yields
b. High biomass yields
c. No effect on biomass yields
d. Decrease with dilution rate until washout
a. Low biomass yields
232
In a continuous reactor, the medium contains 40 g/L of maltose and the medium flow rate is 10 liters per hour and the effluent contains 20 g/L of lactate. What is the productivity of lactate production from this reactor?
a. 50 g-maltose/L
b. 50 g-lactate/L
c. 200 g-maltose/L
d. 200 g-lactate/L
d. 200 g-lactate/L
233
A fed-batch reactor containing 1 g/L of substrate in 2 liter of medium. It is fed with 1 g/L of substrate at the rate of 1 liter per hour. After 10 hours, the concentration of substrate in the reactor was 0.5 g/L. the mass of substrate that was used by the culture in the reactor was
a. 2 g
b. 6 g
c. 8 g
d. 12 g
b. 6 g
234
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.
b. Increase.
c. Increase drastically.
d. Be zero.
a. Decrease abruptly.
235
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.
b. Particles move with the fluid in a fluidized bed bioreactor.
236
In fed-batch fermentation, mass of substrate utilized is calculated using the relationship
a. Initial mass of substrate in the reactor + final mass of substrate in the reactor + flow rate x [substrate in the feed].
b. Initial mass of substrate in the reactor - final mass of substrate in the reactor + flow rate x substrate in the feed
c. Initial mass of substrate in the reactor + final mass of substrate in the reactor - flow rate x [substrate in the feed]
d. Initial mass of substrate in the reactor + final mass of substrate in the reactor - flow rate
b. Initial mass of substrate in the reactor - final mass of substrate in the reactor + flow rate x substrate in the feed
237
A chemostat has a liquid volume of 2 liters and is being fed at a rate of 4 liters per hour. Dilution rate for this reactor will be
a. 2 liters
b. 2 liters per hour
c. 2 h-1
d. 4 liters per hour
c. 2 h-1
238
Mixing per unit volume is observed to be poorest in
a. Continuous packed bed reactor
b. Continuous fluidized bed bioreact
c. Continuous airlift bioreactor
d. None of the above
a. Continuous packed bed reactor
239
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 concentration of glucose in the feed is 10 g/L and the dilution rate is set to 0.4/h, then the steady state concentration of glucose in the effluent will be
a. 0 g/L
b. 0.5 g/L
с. 1.0 g/L
d. 10g/L
b. 0.5 g/L
240
A continuous reactor at steady state contains 0.04 g/L of biomass and 0.02 g/L of phenol. The feed contained 0.1 g/L of phenol. The biomass yield would be
a. 0.4 g/g
b. 0.5 g/g
c.1.0g/g
d. 5.0 g/g
b. 0.5 g/g
241
A culture system with constant environmental conditions maintained through continual provision of nutrient and removal of wastes is called _____ culture system.
a. Continuous
b. Batch
c. Fed-batch
d .Semi continuous
a. Continuous
242
Fed batch reactors is used to produce vinegar because
a. It can maintain low ethanol concentrations.
b. It can maintain low acetic acid concentrations.
c. Acetic acid bacteria tend to ferment at high ethanol concentrations.
d. All of the above
a. It can maintain low ethanol concentrations.
243
When a culture of fermenting yeast becomes metabolically uncoupled, ethanol
a. Becomes a secondary metabolite.
b. Production becomes growth associated.
c. Production becomes non-growth associated.
d. Becomes a growth nutrient.
c. Production becomes non-growth associated.
244
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.
a. Continuous packed bed reactor.
245
On a glucose medium, the growth of an organism is characterized by the following Monod model and stoichiometric parameters: μm = 0.3 h-1, Ks = 0.05 g-l-1 and Yxs = 0.3 g-g-1. When this organism is grown in a 2-liter continuous on a medium containing 10 g/L of glucose added at 1 L/h, the steady state concentration of biomass in the reactor will be
a. 0 g/L
b. 0.4 g/L
c. 0.5 g/L
d. 10 g/L
a. 0 g/L
246
Unsteady state mass balance for dynamic model of continuous stirred tank reactor (CSTR) is
a. Time rate of total amount in reactor = rate of addition to reactor - rate of removal + rate of formation
b. Total amount in reactor = rate of addition to reactor - rate of removal + rate of formation
c. Rate of total amount in reactor = rate of addition to reactor - rate of removal + rate of formation
d. None of the above
a. Time rate of total amount in reactor = rate of addition to reactor - rate of removal + rate of formation
247
A fed-batch reactor initially contains 2 liter of medium. If it was fed at 1 liter per hour, then after 10 hours, the volume of the reactor will be
a. 1 liter
b. 2 liter
c. 3 liter
d. 13 liter
b. 2 liter
248
A Bacillus sp. Produces an antibiotic only during the stationary phase when grown in a batch culture. If grown in a 5 liter continuous culture, the steady state productivity of the antibiotic
a. Will increase until the culture washes out.
b. Will decrease after washout.
c. Will be zero.
d. Will be infinite.
c. Will be zero.
249
In a fluidized bed reactor, the function of the disengagement zone is to
a. Reduce loss of particles from the reactor.
b. Reduce the velocity of the particles near the surface of the reactor.
c. Reduce foaming problems.
d. All of the above.
d. All of the above.
250
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.
c. Fed batch fermenter.
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