A signal-transduction pathway is a series of steps by which a signal on a cell's surface is converted into a specific cellular response. Signal transduction pathways convert signals on a cell's surface into cellular responses.

A signal-transduction pathway is a series of steps by which a signal on a cell's surface is converted into a specific cellular response. Signal transduction pathways convert signals on a cell's surface into cellular responses.

For receptors located on the cell membrane, the signal must be passed on through other molecules in the cell, in a sort of cellular game of "telephone." The chains of molecules that relay signals inside a cell are known as intracellular signal transduction pathways.

In effect, signal transduction is said to have three stages: First, reception, whereby the signal molecule binds the receptor. Then, signal transduction, which is where the chemical signal results in a series of enzyme activations. Finally, the response, which is the resulting cellular responses.

Signal transduction pathway involves the binding of extracellular signaling molecules and ligands to receptors located on the cell surface or inside the cell that trigger events inside the cell, to invoke a response. The response can then alter the cell's metabolism, shape, and gene expression (Krauss, 2006).

Yeast cells secrete a signal molecule called mating factor that attracts them to their mates. Once the mating factor of one yeast binds to the receptor on another yeast, an outgrowth called a "shmoo" forms, which allows the yeast cells to fuse together.

What is a signal transduction pathway? Process by which a signal on a cell's surface is converted to a specific cellular response in a series of steps.