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Some enzymes work together to complete a series of reactions to produce a given product: A + B ------- C ------- D ------------ E Collectively, these steps are known as a metabolic pathway. Enzymes continued. Enzyme 1. Enzyme 2. Enzyme 3. A metabolic pathway.
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Some enzymes work together to complete a series of reactions to produce a given product: A + B ------- C ------- D ------------ E Collectively, these steps are known as a metabolic pathway Enzymes continued Enzyme 1 Enzyme 2 Enzyme 3
Anabolism = chemical reactions that expend energy to make or transform chemical bonds Catabolism = chemical reactions that harvest energy by breaking chemical bonds The entire set of all chemical reactions being performed by an organism is called its metabolism
Catabolism involves exergonic reactions Anabolism involves endergonic reactions
Coenzymes Inhibitors Allosteric regulation Feedback Inhibition Cooperativity Control of Metabolism
Coenzymes are bound at the active site in order to interact with the substrate and play an essential role in the catalysed reaction. They act as carriers of a variety of chemical groups. . Coenzymes
Specific for an enzyme Can be reversible or non-reversible Competitive inhibitors Non-competitive inhibitors Inhibitors
Cells use inhibitors and activators to turn off and on enzymes Many enzymes are controlled by an allosteric site remote from the active site Regulating the rates of enzyme-driven reactions
Allosteric regulation of enzyme activity Many allosterically controlled enzymse show quaternary structure
Feedback inhibition Many enzymes are actually regulated by the end products of the reaction they catalyze Enzyme 1 Enzyme 2 Enzyme 3 Inter- mediate Inter- mediate Start of pathway X Product Presence of product inhibits enzyme 1 This prevents too much product from being made