1. THE PRINCIPLE OF CELL SIGNALING ReceptionTransduction Response

2. CHEMICAL SIGNALING Paracrine signaling Synaptic signaling Endocrine signaling Local signaling Long distance signaling

3. CONTACT-DEPENDENT SIGNALING Gap JunctionCell-Cell Contact

4. RECEPTION OF EXTRACELLULAR SIGNALS Ion Channel-Linked Receptors Enzyme-Linked Receptors G-Protein Coupled Receptors Steroid Receptor

5. STRUCTURE OF ION CHANNEL LINKED RECEPTOR

6. ACTIVATION OF ION CHANNEL- LINKED RECEPTOR Receptor BindingIon Channel Opens Receptor Inactivation

7. STRUCTURE OF G-PROTEIN LINKED RECEPTOR

8. ACTIVATION OF G-PROTEIN LINKED RECEPTORS

10. STRUCTURE OF ENZYME- LINKED RECEPTOR

11. ACTIVATION OF ENZYME- LINKED RECEPTOR Inactive Tyrosine Kinase System Active Tyrosine Kinase System

12. INTRACELLULAR RECEPTOR