We started off this week learning about the signal transduction pathway. The basic gist of the signal transduction pathway is that it starts with a ligand that floats on the outside of the cell. That is the first step to the four step process. The next step, reception, occurs when the ligand bonds perfectly to the receptor protein which is located in the cell membrane. Once the ligand is fitted into the receptor protein, transduction is activated. (Step 3). This all now happens in the cytoplasm. A relay protein was activated during reception, and now activates other relay proteins. The activating of multiple proteins, one after another is called amplification. The fourth step is the response. Below is an image of the signal transduction pathway.