what is a phospholipid, and what is a second messenger?

Question

frostbite · Answer

I will start in the reverse order:
A second messenger is a signal molecule that is being created upon receptor stimulation on the membrane. The idea is that a signal molecule binds a receptor extracellular which in return intracellular synthesis a secondary messenger which can then cause a physiological change.

An example of an hydrophobic second messenger could be a phospholipids. Phospholipids  are characterized by having an phosphate group at the hydrophilic end of the lipid which increases the solubility in water drastically due to the negative charge from the phosphate.

holliemarie · Answer

Thank you so much(: