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Enzymes and Cofactors
Created @February 17, 2022 1:16 PM
Class BIOCHEM
Type Lecture
Materials
Reviewed
To demonstrate the different types of cofactors and enzymes, let’s take a look at the
conversion of phenylalanine → tyrosine (addition of one oxygen atom to form -OH)
Oxygen and Phynylalanine Tetrahydrobiopterin and
phenylalanine are the hydroxylase is the the iron ion in
substrates enzyme (protein) phenylalanine
hydroxylase are
cofactors
Enzymes and Cofactors 1
, Cofactor is a non-protein component of an enzyme
Coenzyme is a cofactor that is consumed and released after use eg.
tetrahydrobiopterin as it is almost like a “sacrificial” substrate
Prosthetic group is a cofactor tightly bound to the enzyme eg. iron ion in
phenylalanine hydroxylase
Enzyme Catalysis
Enzymes lower activation energy to speed up reactions
Activation energy is the minimum amount of energy that must be provided for
compounds to result in a chemical reaction
Enzymes catalyze reactions and lowers the usual activation energy, thus less
energy is required for the reaction to occur
Positioning substrates in the right or ideal position, provide suitable pH or
environment, altering the substrates’ functional group(s)
Cells can decide which reaction to speed up through production of specific
enzymes
Different types of enzymes are needed for different reactions
Cells decide which enzyme to produce based on the final product that the cell
desires
One substrate has many pathways due to different cell types may require
different end products
Pathways can be visualized in a metabolic chart
*Enzymes don’t change the energy of the reaction, but the activation energy*
Enzyme activity is mainly affected by the temperature and pH
In human bodies, there are many hundreds of enzyme-coding genes that are
mutated to form variants
Enzyme Regulation
Gene expression is slow, but enzyme-catalyzed pathways are very dynamic. So how
are enzymes controlled in cells?
An enzyme that catalyzes a reaction with a product that is heavily
interconnected with other pathways are heavly regulated
Enzymes and Cofactors 2
Enzymes and Cofactors
Created @February 17, 2022 1:16 PM
Class BIOCHEM
Type Lecture
Materials
Reviewed
To demonstrate the different types of cofactors and enzymes, let’s take a look at the
conversion of phenylalanine → tyrosine (addition of one oxygen atom to form -OH)
Oxygen and Phynylalanine Tetrahydrobiopterin and
phenylalanine are the hydroxylase is the the iron ion in
substrates enzyme (protein) phenylalanine
hydroxylase are
cofactors
Enzymes and Cofactors 1
, Cofactor is a non-protein component of an enzyme
Coenzyme is a cofactor that is consumed and released after use eg.
tetrahydrobiopterin as it is almost like a “sacrificial” substrate
Prosthetic group is a cofactor tightly bound to the enzyme eg. iron ion in
phenylalanine hydroxylase
Enzyme Catalysis
Enzymes lower activation energy to speed up reactions
Activation energy is the minimum amount of energy that must be provided for
compounds to result in a chemical reaction
Enzymes catalyze reactions and lowers the usual activation energy, thus less
energy is required for the reaction to occur
Positioning substrates in the right or ideal position, provide suitable pH or
environment, altering the substrates’ functional group(s)
Cells can decide which reaction to speed up through production of specific
enzymes
Different types of enzymes are needed for different reactions
Cells decide which enzyme to produce based on the final product that the cell
desires
One substrate has many pathways due to different cell types may require
different end products
Pathways can be visualized in a metabolic chart
*Enzymes don’t change the energy of the reaction, but the activation energy*
Enzyme activity is mainly affected by the temperature and pH
In human bodies, there are many hundreds of enzyme-coding genes that are
mutated to form variants
Enzyme Regulation
Gene expression is slow, but enzyme-catalyzed pathways are very dynamic. So how
are enzymes controlled in cells?
An enzyme that catalyzes a reaction with a product that is heavily
interconnected with other pathways are heavly regulated
Enzymes and Cofactors 2
