Topic overview

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Enzyme activity depends on physicochemical conditions and regulatory inputs. Temperature and pH affect catalytic performance, while substrate and enzyme concentrations influence reaction rate in distinct ways. As substrate becomes abundant, the rate approaches a maximum; accumulated product may oppose forward activity. Inhibitors differ in their effects on apparent affinity and maximum rate: competitive, non-competitive, and uncompetitive inhibition each have characteristic patterns. Activity can also be adjusted by allosteric effectors, cofactors and coenzymes, post-translational modifications, ionic strength, and protein interactions. Reaction timing and tissue-specific isozyme expression add further context. Together, these factors help explain enzyme behavior in physiological settings and in experiments.