1. A signal transduction pathway is a sequence of molecular events and chemical reactions that lead to a cell's response to a signal. This example of a pathway begins with the binding of a growth factor to a protein kinase receptor. The binding unites the two parts of the receptor, which then rearranges to expose protein kinase active sites on the receptor's cytoplasmic domains. The receptor then phosphorylates itself. These initial actions based on growth factor binding will culminate in the ce