Answer:
binding of the hormone molecule with its receptor of the cell.
Explanation:
Hormones are chemical messengers secreted or released by endocrine glands to effect a response in another location called target location. Hormones are proteinous molecules and like every other protein, its function is determined by its shape.
Hormones function or effect their changes by binding to the receptor of the target cell. The hormone recognizes and will only bind to its own receptor molecule on its target cell on order to bring about any change. This defines the specificity of the hormone.
