Definitions of Important Terms
Reception
The target cell will detect a signaling molecule from outside of the cell. The signal molecule will bind to a receptor protein on the surface of the cell or on the inside surface of the cell Target Cell The cell that has receptors for the specific signal molecule Signal Molecule Binds to the receptor and initiates a response, also known as a "ligand" Receptors Proteins on the outside of the cell or the inside of the cell that to which the signaling molecules bind Dimerize (for Tyrosine-Kinase) When the two monomers (units) come together as one with tyrosines projecting from the sides. This unit itself is called a dimer. |
Transduction
When the signaling molecule binds to the receptor protein, it changes it in some way which initiates transduction - changes the signal molecule to elicit a specific cellular response Second Messenger Molecules that relay signals received at receptors on the cell to target molecules elsewhere in the cell, they also amplify the strength of the original signal. EX. cAMP (cyclic adenosine monophosphate) and Ca2+ (calcium) Cascade How the amplification of a signal occurs - involves second messengers Amplification A small signal results in a big response through a cascade Kinase (for Tyrosine-Kinase) Transfers a phosphate group from ATP to a specific molecule |
Response
The effect that the signaling molecule originally wanted on the target cell is achieved EX. body's response to insulin and epinephrine/adrenaline Relay Proteins (for Tyrosine-Kinase) What binds to the phosphorylated (phosphate has been added) tyrosine. Each protein has its own transduction pathway afterwards, triggering a cellular response (with amplification) |