Cooperativity in enzymes refers to the interaction between multiple active sites within an enzyme that can influence substrate binding and catalysis. Positive cooperativity promotes binding of additional substrates, while negative cooperativity inhibits it. Allosteric effectors, molecules that bind outside the active site, can modulate enzyme activity through allosteric regulation. Cooperativity affects enzyme efficiency, substrate affinity, and overall cellular function, with implications for physiological processes and disease development.