Hill's coefficient is an important concept, it is mentioned by all major textbooks but unfortunately it doesnt have a card so i think this is a good place to put it.
Uworld:
The extent to which cooperativity occurs in proteins with multiple binding sites for the same ligand is measured by the Hill coefficient n A Hill coefficient above 1 indicates positive cooperativity, a Hill coefficient of exactly 1 indicates that no cooperativity occurs, and a Hill coefficient below 1 (but greater than 0) indicates negative cooperativity.
Kaplan:
Cooperativity can also be quantified using a numerical value called Hill’s coefficient. The value of Hill’s coefficient indicates the nature of binding by the molecule:
-If Hill’s coefficient > 1, positively cooperative binding is occurring, such that after one ligand is bound the affinity of the enzyme for further ligand(s) increases.
If Hill’s coefficient < 1, negatively cooperative binding is occurring, such that after one ligand is bound the affinity of the enzyme for furt