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WorksheetsBiocatalysis
Total questions: 40
Worksheet time: 30mins
Non steroidal anti inflammatory drugs,
such as aspirin act by inhibiting the
activity of the enzyme:
Lipoxygenase
Cyclooxygenase
Phospholipase
Lipoprotein lipase
An example of lyases is
Glutamine synthetase
Fumarase
Cholinesterase
Amylase
Fischer’s ‘lock and key’ model of the
enzyme action implies that
The active site is complementary in shape to
that of substance only after interaction.
The active site is complementary in shape to
that of substance
Substrates change conformation prior to active
site interaction
The active site is flexible and adjusts to
substrate
From the Lineweaver-Burk plot of
Michaelis-Menten equation, Km and
Vmax can be determined when V is the
reaction velocity at substrate concentra-
tion S, the X-axis experimental data are
expressed as
1/V
V
1/S
S
A sigmoidal plot of substrate concentra-
tion ([S]) verses reaction velocity (V) may
indicate
Michaelis-Menten kinetics
Co-operative binding
Competitive inhibition
Non-competitive inhibition
The kinetic effect of purely competitive
inhibitor of an enzyme
Increases Km without affecting Vmax
Decreases Km without affecting Vmax
Increases Vmax without affecting Km
Decreases Vmax without affecting Km
5. In reversible non-competitive enzyme
activity inhibition
Vmax is increased
Km is increased
Km is decreased
Concentration of active enzyme is reduced
An example of group transferring
coenzyme is
NAD+
NADP+
FAD
CoA
Isoenzymes are
Chemically, immunologically and electro-
phoretically different forms of an enzyme
Different forms of an enzyme similar in all
properties
Catalysing different reactions
Having the same quaternary structures like
the enzymes
Serum alkaline phosphatase level
increases in
Hypothyroidism
Carcinoma of prostate
Hyperparathyroidism
Myocardial ischemia
Serum lipase level increases in
Paget’s disease
Gaucher’s disease
Acute pancreatitis
Diabetes mellitus
The isoenzymes LDH5 is elevated in
Myocardial infarction
Peptic ulcer
Liver disease
Infectious diseases
An example of functional plasma enzyme is
Lipoprotein lipase
Amylase
Aminotransferase
Lactate dehydrogenase
Flipped Pattern of LDH is associated with
Myocardial Infarction
Peripheral Neuropathy
Muscle Wasting
Ventricular Overload
Which of the following is not a reliable marker of MI
BNP
CKMB
Myoglobin
Cardiac Troponin T
Most Specefic Marker of hepatocyte Damage is -
ALT
AST
5'-nucleotidase
GGT
Which of the following is a marker for Prostate Cancer
Serine Protease
Alkaline Phosphatase
Serum prostoclassin
Urine total free deoxypyridinoline
Which of the following isoenzyme of LDH has highest mobility at pH 8.6
H4
MH3
M2H2
M4
When was Translocase Identified as a new class?
2016
2017
2018
2019
Optimum Temperature of Enzymes is
35-40 °C
30-35 °C
40-42 °C
10-20 °C
Significance of Michaelis-Menton Constant is A/E
Signature of an E-S pair
Constant for an E-S pair
Higher the Km, Lower the affinity
Lower the Km, Lower the Affinity
Which of the Following is an allosteric inhibitor of PFK
Citrate
AMP
Fructose-2,6-biP
Acyl CoA
Which is not a method of Covalent Modification of Enzyme Action
Acylation
Acetylation
ADP ribosylation
Sumoylation
Most of the drugs act by which type of inhibition
Uncompetitive
Allosteric
Competetive
Noncompetitive
When end product inhibits the Gene that transcribe for an enzyme, it is called
Feedback inhibition
Feedback Regulation
Gene Sensitisation
Enzyme Alteration
A/E The following follows Sucidal Inhibition
Allopurinol
Aspirin
Difluoro methyl ornithine
Placental ALP
Coenzyme is
Often a vitamin
Always and inorganic compound
Always a protein
Often a metal
Key and lock hypothesis of enzyme action
was given by
Fishcer
Koshland
Buchner
Kuhne
Template/lock and key theory of enzyme
action is supported by
Enzymes speed up reaction
Enzymes occur in living beings and speed
up certain reactions
Enzymes determine the direction of reaction
Compounds similar to substrate inhibit enzyme
activity
Plasma non-functional enzymes are
Totally absent
Low concentration in plasma
important for diagnosis of several disease
All of these
In which diseases of the following organs,
isoenzymes LDH-1 and LDH-2 will be
released in plasma?
Kidney, R.B.C and Liver
Heart, Kidney and R.B.C
Heart, Kidney and Liver
Heart, Lungs and Brain
Serum AST activity is not characteristically
elevated as the result of
Myocardial infarction
Passive congestion of liver
Muscular dystrophies
Peptic ulcer
Which enzyme estimation will be helpful
in differentiating the elevated serum ALP
found in obstructive jaundice as well as
bone disorders?
Serum AST
Serum ALT
Serum LDH
Serum γ-GT
In competitive inhibition which of the
following kinetic effect is true ?
Decreases both Km and Vmax
Increases both Km and Vmax
Decreases Km without affecting Vmax
Increases Km without affecting Vmax
Ribozymes:
RNA enzyme
Non-protein enzyme
Catalyst function
All of these
Different isoenzymes of an enzyme have
the same
Amino acid sequence
Michaelis constant
Catalytic activity
All of these
If the substrate concentration is much
below the km of the enzyme, the velocity
of the reaction is
Directly proportional to substrate concentration
Not affected by enzyme concentration
Nearly equal to Vmax
Inversely proportional to substrate concentration
Kinetics of an allosteric enzyme are
explained by
Michaelis-Menten equation
Lineweaver-Burk plot
Hill plot
All of these
Enzymes accelerate the rate of reactions
by
Increasing the equilibrium constant of reactions
Increasing the energy of activation
Decreasing the energy of activation
Decreasing the free energy change of the
reaction
Lineweaver – Burk double reciprocal plot
is related to
Substrate concentration
Enzyme activity
Temperature
Both A and B
