1. Cell Communication (Signaling) Part 2
AP Biology
Cell Communication (Signaling)
Part 2

2. Phosphorylation and Hydrolysis

3. Receptor Protein

4. G protein Receptor

5. Tyrosine – Kinase Receptor

6. Ion Channel Receptors Signal molecule (ligand) Gate closed Ions Plasma
membrane
Ligand-gated
ion channel receptor
Gate open
Cellular
response
Gate closed

7. Intracellular receptors

8. Secondary Messenger cAMP
Adenylyl cyclase
Phosphodiesterase
Pyrophosphate
H2O P P i
ATP
Cyclic AMP
AMP

9. First messenger
(signal molecule
such as epinephrine)
Adenylyl
cyclase
G protein
G-protein-linked
receptor
GTP
ATP
Second
messenger
cAMP
Protein
kinase A
Cellular responses

10. Secondary Messenger Calmodulin
EXTRACELLULAR
FLUID
Signal molecule
(first messenger)
G protein
DAG
GTP
G-protein-linked
receptor
PIP2
Phospholipase C
IP3 (second
messenger)
IP3-gated
calcium channel
Cellular
re-
sponses
Various
proteins
activated
Endoplasmic
reticulum (ER)
Ca2+
Ca2+
(second
messenger)
CYTOSOL