I

Inhibition

Ki = [I]×Km / ([S](Vm/v − 1))
Quick Reference
Formula / NotationKi = [I]×Km / ([S](Vm/v − 1))
Also Known AsEnzyme inhibition, reaction inhibition, chemical inhibitor, competitive inhibition

What is Inhibition?

The reduction of a chemical reaction rate or enzymatic activity by an inhibitor molecule. Competitive inhibition involves molecules binding to the active site; non-competitive inhibition occurs elsewhere. Inhibition is important in drug design and metabolic regulation.

Formula & Notation

Ki = [I]×Km / ([S](Vm/v − 1))

Other Names / Synonyms: Enzyme inhibition, reaction inhibition, chemical inhibitor, competitive inhibition

Properties & Characteristics

Inhibition in chemistry and biochemistry refers to the reduction of the rate of a chemical or enzymatic reaction by a substance (inhibitor). Enzyme inhibitors can be: competitive (bind to active site, increase apparent Km), non-competitive (bind elsewhere, decrease Vmax), uncompetitive (bind E-S complex), or irreversible (covalently modify enzyme, e.g., DFPP, nerve agents). Chemical inhibitors slow radical chain reactions (antioxidants), corrosion, or polymerisation.

Uses & Applications

Inhibition is exploited in: pharmaceutical drugs (enzyme inhibitors as drugs — statins inhibit HMG-CoA reductase; ACE inhibitors for hypertension; NSAIDs inhibit COX enzymes), food preservation (antioxidants inhibit radical oxidation), corrosion inhibitors in pipelines, and reaction safety (inhibitors in stored monomers prevent premature polymerisation).

Safety Information

Toxic enzyme inhibitors include: organophosphate nerve agents and pesticides (irreversible AChE inhibitors), cyanide (cytochrome c oxidase inhibitor), carbon monoxide (haemoglobin and cytochrome c oxidase inhibitor). Inhibitor removal from stored monomers before polymerisation must be done carefully as uninhibited monomers can rapidly auto-polymerise exothermically.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Inhibition
Formula Ki = [I]×Km / ([S](Vm/v − 1))
Synonyms Enzyme inhibition, reaction inhibition, chemical inhibitor, competitive inhibition

Frequently Asked Questions

The reduction of a chemical reaction rate or enzymatic activity by an inhibitor molecule. Competitive inhibition involves molecules binding to the active site; non-competitive inhibition occurs elsewhere. Inhibition is important in drug design and metabolic regulation.

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