BIOCHEMICAL ENGINEERING Flashcards
Linear inhibition is sometimes called as
A complete inhibition
B incomplete inhibtion
C partial inhibition
D mixed inhibition
COMPLETE INHIBITION
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
STRUCTURALLY SIMILAR TO THE SUBSTRATE
The types of inhibition pattern based on Michaelis Menten equation are
A competitive
B non-competitive
C uncompetitive
D all of the above
COMPETITIVE, NON-COMPETITIVE, UNCOMPETITIVE
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)
THE COMPLEX DISSOCIATION STEP TO PRODUCE PRODUCT
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
KM
Which of these proteases is not a cysteine active site protease?
A Calpain
B Cathepsin D
C Papain
D None of the above
CATHPESIN D
Given an enzyme with a Km = 10m M and Vmax = 100 m mol/min. If [S] = 100 m 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 10 fold increase in Vmax would increase velocity 10 fold y
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
INDUCED FIT
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
NONE OF THE ABOVE
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
it can change the y-intercept
Which category of enzymes belongs to class two in the international classification?
A Hydrolases
B Ligases
C Transferases
D Isomerase
TRANFERASES
The Woolf-Augusteinsson-Hofstee plot of ν versus ν/[S] and the Eadie-Scatchard plot of ν/[S] versus ν do not involve reciprocals of ν 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
SIGNIFICANT
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
HALDANE EQUATION
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
DIXON PLOT
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
DIXON PLOT
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 a fewer substrate molecules can overcome it
THE ACTIVATION ENERGY OF THE REACTION IS LOWERED SO THAT A LARGER PORTION OF THE SUBSTRATE QUALIFIES TO OVERCOME IT
Which of the following common drugs is not a specific enzyme inhibitor?
A Iodine
B Methotrexate
C Sulfbnilamide
D Penicillin
IODINE
The enzyme inhibition can occur by\
A reversible inhibitors
B irreversible inhibitors
C Both (a) and (b)
D None of these
REVERSIBLE AND IRREVERSIBLE INHIBITORS
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
IT CHANGES THE X-INTERCEPT
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
ENZYMES ONLY FUNCTION WHEN THEY ARE IN INTACT CELSS
Non-competitive inhibitor of an enzyme catalyzed reaction
A decreases Vmax
B binds to Michaelis complex (ES)
C both (a) and (b)
D can actually increase reaction velocity in rare cases
decreases Vmax
binds to Michaelis complex (ES)
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 TEMPORARY ASSOCIATION
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
0.115
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
LINEWEAVER BURK PLOT
LANGMUIR PLOT
EADIE HOFSTEE PLOT
Quasi steady state is also known as
A Michaelis Menten approach
B Briggs-Haldane approach
C Pseudo steady state
D all of the above
PSEUDO STEADY STATE
Which of these enzymes contains a Zinc (Zn) ion?
A Carboxypeptidase A
B Phosphorylase B kinase
C Tyrosine hydroxylase
D Phosphodiesterase
Carboxypeptidase A
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
increases KM and reduces Vmax
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 faster
PARTICIPATES IN FEEDBACK REGULATION
Which of the following activity is possible by transferases?
A Transfer of methyl groups
B Transfer of glycosyl group
C Both (a) and (b)
D None of these
Transfer of methyl groups
Transfer of glycosyl group
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
reversibly to the enzyme substrate complex yielding an inactive ESI complex
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
HILL PLOT
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
SPECIFIC ACTIVITY
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
(ν0 - νi)/ν0
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))
rmaxS/(Km (1+I/Ki)+S))
Classical noncompetitive inhibition is obtained only under
A slow equilibrium conditions
B moderate equilibrium conditions
C rapid equilibrium conditions
D non-equilibrium conditions
RAPID EQUILLIBRIUM CONDITIONS
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
rate of addition - rate of removal + rate of formation = 0
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
0.66
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
COMPETITIVE INHIBITION IS GREATER THAN UNCOMPETITIVE INHIBITION
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
13.54μ moles liter-1min-1
The rate equation in non-competitive inhibition based on Michaelis Menten equation is given by
A rmaxS/(Km + S)(1+I/Ki)
B rmaxE/(Km (1+I/Ki)+S))
C VmaxS/(Km + S)(1+I/Ki)
D rmaxS/Km
rmaxS/(Km + S)(1+I/Ki)
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
ENZYMES PROVIDE ACTIVATION ENERGY FOR REACTIONS
The slope of Lineweaver Burk plot for Michaelis Menten equation is
A Vmax/Km
B Km/Vmax
C 1/Km
D Km.Vmax
Km/Vmax
The initial velocity, V0, of an enzyme catalyzed reaction reaches Vmax as
A [S] = KM
B [S] = 10 * KM
C 1/[S] = 1/KM
D 1/[S] → 0
1/[S] → 0
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
Michaelis Menten approach
Briggs-Haldane approach
Numerical solution approach
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
ALL OF THESE
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
THE PRODUCT RELEASING STEP
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
0.5 * Vmax
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
NO EFFECT ON SUBSTRATE BUILDING AND VICE VERSA
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
CATALYZES A CHEMICAL REACTION
Enzymes are basically
A proteins
B vitamins
C fat
D carbohydrate
PROTEINS
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
d(CES)/dt = 0
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
DECREASING ENERGY OF ACTIVATION
Which category of enzymes belongs to class 5 in the international classification?
A Hydrolases
B Isomerases
C Oxido-reductases
D Cyclase
ISOMERASES
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 product
ENZYME AND SUBSTRATE
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 substrate to product
THE RATE AT WHICH THE ENZYME CAN CONVERT SUBSTRATE TO PRODUCT
The equation for the rate of product formation for simple enzyme reaction is given by (Where rmax, maximum reaction rate, Cs substrate concentration, Cp product concentration ES, CES enzyme-substrate concentration)
A rp = rmax Cs/(Km+Cs)
B rp= rmax CES/(Km+ CES)
C rp = rmax Cs/(Km+CES)
D rp = rmax Cs/(Km+Cp)
rp = rmax Cs/(Km+Cs)
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
0.1 * Vmax
β-amylase is
A endoenzyme
B exoenzyme
C saccharifying enzyme
D both (b) and (c)
EXOENZYME
SACCHARIFYIN ENZYME
Juice clarification extraction is facilitated by using
A cellulases
B amylase
C inulinase
D lactase
CELLULASES
Lysozyme is naturally present in
A egg white
B bacteria
C tears & milk
D all of these
EGG WHITE, BACTERIA, TEARS AND MILK
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
ALL A B C
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
TO STABILIZE MASHING
The bitter taste of the high protein materials is reduced by using
A invertase
B dectinase
C protease
D none of these
PROTEASE
Sulphydryl oxidase is used for
A discoloration
B clarification of images
C UHT milk off flavour removal
D all of these
UHT MILK OFF FLAVOR REMOVAL
α-amylase is an endo enzyme which requires
A Ca
B Cu
C Mn
D None of these
CA
Liquefaction of starch to dextrin is carried out by
A α-amylase
B cellulase
C pectinase
D all of these
α-amylase
Which is true about rennet?
A It is a mixture of protease chymosin and pepsin
B It is a mixture of rennin and pepsin
C Both (a) and (b)
D none of the above
It is a mixture of protease chymosin and pepsin
It is a mixture of rennin and pepsin
Milk digestibility is improved by using
A RNase
B lactase
C β-amylase
D none of these
LACTASE
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
α-amylase
Gluco-isomerase
Gluco-amylase
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
catalyses hydrolysis of β-1-4 linkages between N-acetyl muranic acid and N-acetyl glucosamine in peptideoglycan
Hersperidinase is used for
A juice clarification
B juice debittering
C off flavour reduction
D RNA reduction in fish
JUICE CLARIFICATION
Which of the following metallic ion is there in ascorbic acid oxidase?
A Mg
B Fe
C Cu
D Mn
CU
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
GLUCOSE OXIDASE-CATALASE
The enzyme used to reduce bitterness of grapes commonly contains
A α-L-rhamonosidase
B β-d-glucosidase
C β- galactosidase
D both (a) and (b)
α-L-rhamonosidase
β-d-glucosidase
Citrus juice debittering can be carried out using
A limoninase
B inulinase
C anthocyanase
D None of these
LIMONINASE
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
THIAMINASE
Soya off flavour removal may be achieved using
A di acetyl reductase
B β- amylase
C aldehyde oxidase
D protease
ALDEHYDE OXIDASE
The reduction in off flavour of beer is practiced through
A hersperidinase
B rnase
C invertase
D diacetyl reductase
DIACETYL REDUCTASE
Discoloration can be achieved by using
A sulphloydryl oxidase
B proteases
C anthocyanase
D all of these
ANTHOCYANASE
The prosthetic group present in phenolase enzyme is
A Mg
B Cu
C Ca
D Fe
CU
Enzymes degrade, alter or synthesize a food component through
A oxidation/reduction/isomerization
B hydrolysis/synthesis
C group transfer
D all of the above
oxidation/reduction/isomerization
hydrolysis/synthesis
group transfer
The enzyme β-galactosidase is also known as
A lactase
B EC3.2.1.23
C both (a) and (b)
D isomerase
lactase
EC3.2.1.23
Chymosin hydrolyses the bond between
A Alanine and glycine
B Phenyl alanine and methonine
C Glutamic acid and alanine
D Alanine and phenyl alanine
PHENYL ALANINE AND METHONINE
The function of the disengagement zone in an airlift fermenter is to
A prevent CO2 rich bubbles from entering the downcomer
B reduce the velocity of the bubbles
C reduce liquid loss as aerosols
D all of the above
ALL OF THE ABOVE
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
NO FURTHER INCREASE IN THE CELL POPULATION AFTER MAXIMUM VALUE
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
increase and the division rate increases to reach a maximum
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
WILL INCREASE WITH THE CONCENTRATION OF THE GROWTH LIMITING SUBSTRATE UNTIL IT REACHES A MAXIMUM VALUE
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
BOTH ACID AND ALCOHOL
The function of a mechanical seal is to
A prevent contaminants entering the reactor
B prevent cells from leaving the reactor
C both (a) and (b)
D prevent air to enter
PREVENT CONTAMINANTS ENTERING THE REACTOR
PREVENT CELLS FROM LEAVING THE REACTOR
The phenomenon in which substrates are used in a sequential manner is known as
A trans-substrate genesis
B dialism
C diauxie
D multiplicity
DIAUXIE
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
F/VR
Diauxie is
A growth factors
B microbiological die off
C the simultaneous uptake of nutrients
D the stagewise uptake of nutrients
THE STAGEWISE UPTAKE OF NUTRIENTS
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-organisms is removed is called
A manostat
B chemostat
C turbidostat
D culturostat
CHEMOSTAT
In the death phase
A nutrients available for the cells are depleted 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
NUTRIENTS AVAILABLE FOR THE CELLS ARE DEPLERED AND BEGIN TO DIE
The maximum specific growth rate of an organism depends on
A medium composition
B temperature
C pH
D All of these
MEDIUM COMPOSITION, TEMPERATURE, PH
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
THE MONOD MODEL WAS DERIVED FROM AN ANALYSIS OF THE MECHANISM OF MICROBIAL GROWTH
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
LARGE HEIGTH TO DIAMETER RATIO
Why a T-flask used in small-scale cell culture is incubated in a horizontal position?
A To save space
B To increase the surface area of the liquid-air interface
C Both (a) and (b)
D To increase the rate of oxygen transfer into the liquid
To save space
To increase the surface area of the liquid-air interface
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
TURBIDOSTAT
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
DILUTION RATE IS HIGHER THAN THE MAXIMUM SPECIFIC GROWTH RATE
Fermentor should be filled with medium upto
A 65-70%
B 70-75%
C 75-80%
D 80-85%
75% TO 80%
Bacterial growth curve is obtained by plotting
A number of cells versus time
B number fo spores versus time
C log of number of cells versus time
D log of number of cells survived versus time
LOG OF NUMBER OF CELLS VERSUS TIME
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
PERMEABILIZE
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 bioreactor
CONTINUOUS PACKED BED REACTOR
The function(s) of the draft tube in an airlift bioreactor is
A to reduce bubble coalescence
B to improve circulation
C to even out shear conditions throughout the reactor
D all of the above
TO REDUCE BUBBLE COALAESCENCE
TO IMPROVE CIRCULATION
TO EVEN OUT SHEAR CONDITIONS THROUGHOUT THE REACTOR
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
SPECIFIC GROWTH RATE TO THE SUBSTRATE AVAILABILITY
The height to diameter ratio (H/D) for the column fermenters is
A <3
B >3
C <1.5
D >1.5
> 3
