Final answer:
The 3 major properties of target cell receptor-hormone interactions are specificity, which ensures hormones affect only target cells with matching receptors, affinity, which is the strength of hormone-receptor binding, and sensitivity, which is the degree of cellular response to the hormone.
Step-by-step explanation:
The three major properties of target cell receptor-hormone interactions are specificity, affinity, and sensitivity. Specificity refers to the precise matching of a hormone to its unique receptor on a target cell, ensuring that hormones trigger a response only in their specific target cells. Affinity describes the strength of the binding between a hormone and its receptor; a high affinity means the hormone is readily and tightly bound to the receptor.
Sensitivity relates to the extent to which a target cell responds to a given hormone concentration, which can be determined by the number of receptors available on the cell surface; more receptors generally make a cell more responsive to the hormone.