Quick question on signal transduction

[lbeste12]

This topic...seriously confuses me haha.

So signal transduction can occur with both lipid soluble molecules and non-lipid soluble molecules.

The non-lipid soluble molecules attach to a receptor which activates cAMP etc etc etc
This process is also faster?

The lipid soluble molecules diffuse across the cell membrane and undergo a different process? So, they don't do the whole cAMP thing?
They are also generally slower?



So confusing!

[dou0014]

Lipid Soluble molecule can get through the plasma membrane and bind to a receptor in the cytosol to ilicit signal transduction and a response. however as they are hydrophobic they require a carrier molecule to travel in blood.  eg Testosterone

In contrast, protein based hormones (Insulin etc) Cannot get through the plasma membrane, but don't need a carrier molecule to travel through blood.  They bind to a receptor on the surface of the plasma membrane, and a second messenger molecule such a a G carrier protein is activated, which enters into the cytoplasm to bind to receptor and elicit response. Hope that helps.  Signal transduction is a cascade of events, linking an external signal to a response. The response part is important.

[Zebra]

is signal transduction referring to the activation of second messenger or everything that occurs in the cell once an external signal is introduced??