Enzyme Activators and Inhibitors - Study Notes

The activity of enzymes can be influenced by activators and inhibitors.
Activators increase enzyme activity; inhibitors decrease enzyme activity.
Enzyme inhibitors are quite common and play significant roles in nature, medicine, and agriculture.

Activators are substances that increase the activity of enzymes.
They can modulate metabolic pathways by enhancing catalytic performance, though specific examples are not listed in the transcript.

Inhibitors decrease enzyme activity.
Plants synthesize enzyme inhibitors as a defense against herbivores.
Pesticides and herbicides often target enzymes to inactivate them.
Many drugs used in medicine are enzyme inhibitors.
Antibiotics used to treat bacterial infections are enzyme inhibitors. Example: penicillin is an inhibitor of an enzyme that some bacteria use to build their cell walls; by inhibiting this enzyme, penicillin kills the bacteria.
Some drugs used to treat cancer (or uncontrolled cell division) are enzyme inhibitors, such as methotrexate.
Poisons like cyanide are also enzyme inhibitors.
Given the importance of chemical reactions and the role of enzymes in metabolism, enzyme inhibitors have widespread applications.

Irreversible inhibitors form covalent bonds with enzymes and irreversibly inactivate them.
Reversible inhibitors form weak bonds with enzymes and therefore easily dissociate.

Enzyme inhibitors have broad applications due to the central role of enzymes in metabolism.
Applications span medicine (treatment of infections, cancer therapy), agriculture (pesticides/herbicides), and toxicology (poisons).

Regulation of enzyme activity through activators and inhibitors is a fundamental aspect of metabolism and pharmacology, underpinning therapeutic strategies and ecological interactions.