Final answer:
Enzyme cooperativity is when the binding of a substrate to one active site on an enzyme affects the binding of additional substrates on the same enzyme. It is applicable to allosteric enzymes that can experience changes to their substrate affinity through conformational changes initiated by substrate binding. This illustrates the mechanism behind allosteric regulation, particularly in enzymes with multiple subunits.
Step-by-step explanation:
Enzyme cooperativity refers to a scenario where the binding of a substrate to one active site of an enzyme affects the binding of additional substrate molecules to other active sites on the same enzyme. This concept is particularly applicable to allosteric enzymes, which have more than one binding site and can undergo conformational changes that either increase or decrease their affinity for the substrate upon activator or inhibitor binding. Allosteric enzymes can be regulated through the cooperative binding of multiple substrate molecules, which relates to the correct option (a) - Binding of multiple substrates; Allosteric enzymes.
Unlike competitive enzyme inhibition, where the inhibitor competes with the substrate for the active site, or noncompetitive inhibition, where the inhibitor binds to an allosteric site and changes the active site conformation, enzyme cooperativity typically involves an increase in enzymatic activity as substrate concentration increases, following the initial substrate binding. Moreover, this phenomenon does not relate to competitive enzymes, which typically have substrate specificity for their active sites, nor does it involve the inhibition of enzyme activity by noncompetitive inhibitors or the inactivation of cofactors by irreversible enzymes.