z Cell Communication Chapter 11 z Cell Junctions

z Cell Communication Chapter 11

z § Cell Junctions § Gap, Tight, Plasmodesmata § Cell-cell Recognition § Like the immune system! Communication

z Signaling § Local – Paracrine (molecules like growth factors) and Synaptic (neurotransmitters) § Long Distance – Endocrine (hormones that travel in bloodstream)

z Signal Transduction Pathway

z G- Protein Coupled Receptor

Animation that shows both G-protein and ion channels: Click here

z Tyrosine-Kinase Receptor

Animation: https: //www. youtube. com/watch? v=ki. HAdan 2 AOY

z Ion Channel Receptor

z z z Amplification

Phosphorylation Cascade z

z Second Messengers § Non-protein § Cyclic AMP (c. AMP) § Adenylyl cyclase converts ATP into c. AMP § Phosphodiesterase converts c. AMP into AMP (so it shuts off the second messenger) § Animation: http: //highered. mheducation. com/site s/0072507470/student_view 0/chapter 17/animation__second_messenger_ _camp. html

z § Ca 2+ § Higher concentration in ER and Mitochondria and outside the cell § Low concentration in cytosol § Calcium-ion pumps located in ER, Mitochondria, Cell Membrane Second Messengers (Con’t)

z z Growth Factors § Don’t directly turn on genes § Turns on transcription factor to turn on a gene § DO NOT ENTER THE CELL

z z Intracellular Signaling § Lipid-soluble hormones (steroids) can go into the cell because their receptor is in the cell! § Animation: http: //highered. mheducation. c om/sites/0072507470/student _view 0/chapter 17/animation_ _intracellular_receptor_model. html

z Cell Death (Apoptosis) § Death signal (morbid, I know) comes in § Cascade begins when Ced-4 and Ced-3 activate (you don’t need to know specifics)