BI110 Chapter Notes - Chapter 20: Signal Transduction, Macrophage, Receptor Tyrosine Kinase
Document Summary
Cells use signaling molecules & receptors to communicate. Communicate in response to environmental cues (light, heat, touch, pressure, chemicals) Must recognizing each other, coordinate activity, & respond to stimuli. Example: cancerous tumors grow when macrophages fail to recognize cancer cells as non-self. Mechanism cells use to share information response to extracellular signals. Involves info exchange b/w neighboring cells as well as with those farther away. Cells that respond to stimulus called sensory cells. Secrete ligands: signaling molecules that bind directly to receptor on target cells to produce response. Signaling molecules = hormones (chemical messengers secreted by glands & neurotransmitters), chemicals produced by ns. Serve as signals that cue target cells to respond in particular way to alter physiology. Adjacent cells can use direct contact to communicate. Gap junctions provide transmission channels b/w adjacent cells. Plasmodesmata are plant gap junction mechanism of direct contact. Communication b/w synapses of neurons through release of neurotransmitter diffuse into synaptic cleft ( no physical contact)
