1. Cell Signaling

2. Local Signaling Paracrine Paracrine Synaptic Synaptic

3. Long-distance Signaling Endocrine Endocrine Hormones

4. Stages of Cell Signaling

5. Reception Reception  Ligand (signaling molecule) binds to receptor protein  RP shape change stimulates transduction pathway

6. Stages of Cell Signaling Intracellular reception Intracellular reception  Nonpolar signals bind to receptors in cytosol or nucleus

7. Stages of Cell Signaling Transduction Transduction  Various molecules relay signal to response location

8. Inactive kinase 1 Phosphorylation cascade Inactive kinase 2 Active kinase 1 Active kinase 2 Active enzyme Inactive enzyme Cellular response ADP Activated relay molecule Stages of Cell Signaling Phosphorylation Kinase activates molecule by adding a phosphate group

9. Inactive kinase 1 Phosphorylation cascade Inactive kinase 2 Active kinase 1 Active kinase 2 Active enzyme Inactive enzyme Cellular response ADP Activated relay molecule Stages of Cell Signaling Dephosphorylation Phosphatase deactivates molecule by removing a phosphate group

10. Stages of Cell Signaling Response Response

11. Stages of Cell Signaling