PRELIM 04 - Enzyme Inhibition and Regulation Flashcards
Binds directly on the active site (Types of inhibitors)
Competitive inhibitors
Binds to allosteric sites (Types of inhibitors)
Non-competitive inhibitors
Similar to noncompetitive inhibitors; binding of inhibitor affects binding of substrate (Types of inhibitors)
Mixed non-competitive inhibitors
Binds directly to the enzyme-substrate complex, but not to free the enzyme; distorts the active site (Types of inhibitors)
Uncompetitive inhibitors
Applicable in multi-step pathways; an end product inhibits key enzymes which form the intermediates (Forms of enzyme regulation)
Feedback inhibition
An enzyme which initiates the reaction for the synthesis of cytidine triphosphate (CTP)
Aspartate transcarbamyolase (ATCase)
Allosteric regulators binds to regulatory sites to regulate catalytic activity (Forms of enzyme regulation)
Allosteric regulation
__________ is an activator of ATCase
Adenosine triphosphate (ATP)
__________ is an inhibitor of ATCase
Cytidine triphosphate (CTP)
Conformational transitions affect substrate binding
Taut (T) and relaxed (R) conformations
Model that presents that the presence of substrate affects the equilibrium towards R conformation
Concerted model
__________ bind to favor T conformation
Allosteric inhibitors
__________ bind to favor R conformation
Activators
Model that presents the sequential activation of the subunits upon binding of a substrate to one of the catalytic sites of a multi-domain enzyme
Sequential model
Involves the introduction of a group to the enzyme either to activate or deactivate the enzyme (Forms of enzyme regulation)
Covalent modification
