Enzymology kinetics
Enzyme Kinetics and Km - correct answer-The reaction catalysed by an enzyme uses
exactly the same reactants and produces exactly the same products as the uncatalysed
reaction. Like other catalysts, enzymes do not alter the position of equilibrium between
substrates and products.
Enzyme-catalysed reactions display saturation kinetics:
For a given enzyme concentration and for relatively low substrate concentrations, the
reaction rate increases linearly with substrate concentration; the enzyme molecules are
largely free to catalyze the reaction, and increasing substrate concentration means an
increasing rate at which the enzyme and substrate molecules encounter one another.
However, at relatively high substrate concentrations, the reaction rate asymptotically
approaches the theoretical maximum; the enzyme active sites are almost all occupied and
the reaction rate is determined by the intrinsic turnover rate of the enzyme. The substrate
concentration midway between these two limiting cases is denoted by KM.
Enzymes related to MI - correct answer-Creatine Kinase
Troponin T
Lactate Dehydrogenase
Enzyme usually measured to diagnose Liver Damage - correct answer-Alanine
Aminotransferase
Enzyme - correct answer-Enzymes are proteins that catalyze (i.e., increase the rates of)
chemical reactions: Highly specific catalysts
They just change the rate and can not alter the equlibrium.
In enzymatic reactions, the molecules at the beginning of the process are called substrates,
and the enzyme converts them into different molecules, called the products
Induced fit model - correct answer-Substrate binding > Conformational change of enzyme >
Energy produced in favor of reaction
Types of Enzymes - correct answer-Oxidoreductase
Hydrolase
Lyase
Transferase
Isomerase
Ligase
Non protein components which aid Enzymes - correct answer-Cofactor:
1) Coenzyme
2) Prosthetic groups
, A cofactor is a non-protein chemical compound that is bound to a protein and is required for
the protein's biological activity. These proteins are commonly enzymes, and cofactors can be
considered "helper molecules" that assist in biochemical transformations.
Cofactors can also be classified depending on how tightly they bind to an enzyme, with
loosely-bound cofactors termed coenzymes and tightly-bound cofactors termed prosthetic
groups.
Important examples: Metals, Vit B Complex
Apoenzyme vs. Holoenzyme - correct answer-An inactive enzyme, without the cofactor is
called an Apoenzyme, while the complete enzyme with cofactor is the Holoenzyme.
Isozyme - correct answer-Isozymes (also known as isoenzymes) are enzymes that differ in
amino acid sequence but catalyze the same chemical reaction.
These enzymes usually display different kinetic parameters (e.g. different KM values), or
different regulatory properties.
The existence of isozymes permits the fine-tuning of metabolism to meet the particular
needs of a given tissue or developmental stage
Michaelis-Menten kinetics - correct answer-Approximately describes the kinetics of many
enzymes.
Relevant to situations where very simple kinetics can be assumed, (i.e. there is no
intermediate or product inhibition, and there is no allostericity or cooperativity). More
complex models exist for the cases where the assumptions of Michaelis-Menten kinetics are
no longer appropriate.
The Michaelis-Menten equation: The effect of Substrate Concentration on Reaction Kinetics
Michaelis Constant - correct answer-Km
The substrate concentration when the Initial Velocity (Vo or Vi) is half of the Vmax
Thermodynamics vs Kinetics - correct answer-Thermodynamics: The Energy states of a
system, and the reaction Direction
Concepts like ΔG, Exergonic, Endergonic, Reaction Direction and Equilibriubrium
Kinetics: The Rate of the reaction and factors that affect the Rate
Enzymes just alter the Kinetics (rate) of the reaction and have no effect on reaction
equilibrium
Reactant Kinetic Energy - correct answer-Attaining activation energyn requires an increase
in reactant kinetic energy:
1) Temprature
2) Substrate Concentration
Methods to increase the Rate of the reaction: - correct answer-1) Increase Temprature
Enzyme Kinetics and Km - correct answer-The reaction catalysed by an enzyme uses
exactly the same reactants and produces exactly the same products as the uncatalysed
reaction. Like other catalysts, enzymes do not alter the position of equilibrium between
substrates and products.
Enzyme-catalysed reactions display saturation kinetics:
For a given enzyme concentration and for relatively low substrate concentrations, the
reaction rate increases linearly with substrate concentration; the enzyme molecules are
largely free to catalyze the reaction, and increasing substrate concentration means an
increasing rate at which the enzyme and substrate molecules encounter one another.
However, at relatively high substrate concentrations, the reaction rate asymptotically
approaches the theoretical maximum; the enzyme active sites are almost all occupied and
the reaction rate is determined by the intrinsic turnover rate of the enzyme. The substrate
concentration midway between these two limiting cases is denoted by KM.
Enzymes related to MI - correct answer-Creatine Kinase
Troponin T
Lactate Dehydrogenase
Enzyme usually measured to diagnose Liver Damage - correct answer-Alanine
Aminotransferase
Enzyme - correct answer-Enzymes are proteins that catalyze (i.e., increase the rates of)
chemical reactions: Highly specific catalysts
They just change the rate and can not alter the equlibrium.
In enzymatic reactions, the molecules at the beginning of the process are called substrates,
and the enzyme converts them into different molecules, called the products
Induced fit model - correct answer-Substrate binding > Conformational change of enzyme >
Energy produced in favor of reaction
Types of Enzymes - correct answer-Oxidoreductase
Hydrolase
Lyase
Transferase
Isomerase
Ligase
Non protein components which aid Enzymes - correct answer-Cofactor:
1) Coenzyme
2) Prosthetic groups
, A cofactor is a non-protein chemical compound that is bound to a protein and is required for
the protein's biological activity. These proteins are commonly enzymes, and cofactors can be
considered "helper molecules" that assist in biochemical transformations.
Cofactors can also be classified depending on how tightly they bind to an enzyme, with
loosely-bound cofactors termed coenzymes and tightly-bound cofactors termed prosthetic
groups.
Important examples: Metals, Vit B Complex
Apoenzyme vs. Holoenzyme - correct answer-An inactive enzyme, without the cofactor is
called an Apoenzyme, while the complete enzyme with cofactor is the Holoenzyme.
Isozyme - correct answer-Isozymes (also known as isoenzymes) are enzymes that differ in
amino acid sequence but catalyze the same chemical reaction.
These enzymes usually display different kinetic parameters (e.g. different KM values), or
different regulatory properties.
The existence of isozymes permits the fine-tuning of metabolism to meet the particular
needs of a given tissue or developmental stage
Michaelis-Menten kinetics - correct answer-Approximately describes the kinetics of many
enzymes.
Relevant to situations where very simple kinetics can be assumed, (i.e. there is no
intermediate or product inhibition, and there is no allostericity or cooperativity). More
complex models exist for the cases where the assumptions of Michaelis-Menten kinetics are
no longer appropriate.
The Michaelis-Menten equation: The effect of Substrate Concentration on Reaction Kinetics
Michaelis Constant - correct answer-Km
The substrate concentration when the Initial Velocity (Vo or Vi) is half of the Vmax
Thermodynamics vs Kinetics - correct answer-Thermodynamics: The Energy states of a
system, and the reaction Direction
Concepts like ΔG, Exergonic, Endergonic, Reaction Direction and Equilibriubrium
Kinetics: The Rate of the reaction and factors that affect the Rate
Enzymes just alter the Kinetics (rate) of the reaction and have no effect on reaction
equilibrium
Reactant Kinetic Energy - correct answer-Attaining activation energyn requires an increase
in reactant kinetic energy:
1) Temprature
2) Substrate Concentration
Methods to increase the Rate of the reaction: - correct answer-1) Increase Temprature
