Presentation on theme: "AP Biology Chapter 11 Cell Communication AP Biology Gap junctions between animal cells Cell-Cell Communication Animal cells use gap junctions to send."— Presentation transcript:
AP Biology Chapter 11 Cell Communication
AP Biology Gap junctions between animal cells Cell-Cell Communication Animal cells use gap junctions to send signals Cells must be in direct contact Protein channels connecting two adjoining cells
AP Biology Cell-Cell Communication Plasmodesmata between plant cells Plant cells use plasmodesmata to send signals Cells must be in direct contact Gaps in the cell wall connecting the two adjoining cells together
AP Biology Local Signaling Other types of signaling over a short distance Cell-cell recognition Membrane bound cell surface molecules Glycoproteins Glyolipids Local regulators Growth factors Only work over a short distance
AP Biology Long-Distance Signaling Nervous System in Animals Electrical signals through neurons Endocrine System in Animals Uses hormones to transmit messages over long distances Plants also use hormones Some transported through vascular system Others are released into the air
AP Biology Reception 1 EXTRACELLULAR FLUID Receptor Signaling molecule Plasma membrane CYTOPLASM 1 Three Stages of Cell Signaling Signaling molecule binds to the receptor protein The receptor and signaling molecules fit together (lock and key model, induced fit model, just like enzymes!)
AP Biology Three Stages of Cell Signaling Reception 1 EXTRACELLULAR FLUID Receptor Signaling molecule Plasma membrane CYTOPLASM 1 Relay molecules in a signal transduction pathway Transduction 2 The signal is converted into a form that can produce a cellular response 2 nd Messenger!
AP Biology EXTRACELLULAR FLUID Plasma membrane CYTOPLASM Receptor Signaling molecule Relay molecules in a signal transduction pathway Activation of cellular response Reception TransductionResponse Three Stages of Cell Signaling The transduced signal triggers a cellular response Can be catalysis, activation of a gene, triggering apoptosis, almost anything!
AP Biology G protein-coupled receptor Plasma membrane Enzyme G protein (inactive) GDP CYTOPLASM Activated enzyme GTP Cellular response GDP P i Activated receptor GDP GTP Signaling molecule Inactive enzyme G-Protein Receptors
AP Biology Signaling molecule (ligand) Gate closed Ions Ligand-gated ion channel receptor Plasma membrane Gate open Cellular response Gate closed Ion Channel Receptors Very important in the nervous system Signal triggers the opening of an ion channel depolarization Triggered by neurotransmitters
AP Biology Fig Signaling molecule Receptor Activated relay molecule Inactive protein kinase 1 Active protein kinase 1 Inactive protein kinase 2 ATP ADP Active protein kinase 2 P P PP Inactive protein kinase 3 ATP ADP Active protein kinase 3 P P PP i ATP ADP P Active protein PP P i Inactive protein Cellular response Phosphorylation cascade i Transduction: A Phosphorylation Cascade
AP Biology First messenger Fig G protein Adenylyl cyclase GTP ATP cAMP Second messenger Protein kinase A G protein-coupled receptor Cellular responses Transduction in a G-protein pathway
AP Biology Response Many possible outcomes This example shows a transcription response Growth factor Receptor Phosphorylation cascade Reception Transduction Active transcription factor Response P Inactive transcription factor CYTOPLASM DNA NUCLEUS mRNA Gene
AP Biology Specificity of the signal The same signal molecule can trigger different responses Many responses can come from one signal! Signaling molecule Receptor Relay molecules Response 1 Cell A. Pathway leads to a single response. Cell B. Pathway branches, leading to two responses. Response 2Response 3
AP Biology The signal can also trigger an activator or inhibitor The signal can also trigger multiple receptors and different responses Response 4Response 5 Activation or inhibition Cell C. Cross-talk occurs between two pathways. Cell D. Different receptor leads to a different response.
AP Biology Any Questions?? Can You Hear Me Now?