What is signal pathway?
Signal pathway is the process by which an extracellular signaling molecule activates a membrane receptor, that in turn alters intracellular molecules creating a response.
There are two stages in this process:
1) a signalling molecule activates a certain receptor on the cell membrane.
2) The stimulated receptor on the cell membrane further causes a second messenger to continue the signal into the cell and elicit a physiological response.
In either step, the signal can be amplified, meaning that one signalling molecule can cause many responses.
Who is the first guy who found it?
Dr. Martin Rodbell (December 1, 1925 – December 7, 1998), an American biochemist and molecular endocrinologist, who discovered G-proteins and their roles in signal transduction in cells.
The web link: http://en.wikipedia.org/wiki/Signal_transduction
