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MYROFORA PANAGI. HOW DO ENZYMES ACHIEVE SPECIFICITY. ENZYMES : BILOGICAL CATALYSTS. Almost all enzymes are globular proteins Some are riboenzymes – RNA molecules They are found in membranes of: Endoplasmatic reticulum Mitochondria Chloroplasts Golgi apparatus. Function:
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MYROFORA PANAGI HOW DO ENZYMES ACHIEVE SPECIFICITY
ENZYMES: BILOGICAL CATALYSTS • Almost all enzymes are globular proteins • Some are riboenzymes – RNA molecules They are found in membranes of: • Endoplasmatic reticulum • Mitochondria • Chloroplasts • Golgi apparatus
Function: Low the activation energy for a reaction increase the rate of the reaction Properties of enzymes: • Have active site • Specificity • Increase the rate of biological reactions by lowering the activation energy • Are not consumed by the reactions they catalyze • Nor do they alter the equilibrium of the reactions
Mechanism of enzyme's function: The substrate binds on a specific region of enzyme, known as the active side and form a temporary enzyme-substrate complex the termination of the reaction (products).
Specificity Enzymes are highly specific both in reactions that they catalyze and in their choice of substrates. Hydrophilic/hydrophobic characteristics, complementary shape and charge are factors that determine the specificity of an enzyme.
Factors that affect the functionof enzymes: • Temperature • Chemical denaturants (pH) A high temperature or pH cause the denaturation of an enzymeand the disruption of the three-dimensional structure result: the enzyme becomes unfolded and inactivated
Enzyme concentration • Substrate concentration The enzyme concentration or the substrate concentration affect the rate of the reaction
However, enzymes can be inhibited by specific molecules • Irreversible inhibitors: bond tightly to the active side of the enzyme permanent ex: drugs, poison
Reversible inhibitors: • Competitive:because of the structure similarity bind at the active side and thus prevents the substrate from binding • Non-competitive: bind in other side of an enzyme apart active side and disfigure it