BIOL130 Lecture Notes - Lecture 8: Salivary Gland, Artificial Cardiac Pacemaker, Thyroid
27 Feb 2015
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Why do we need communication: mating, development, growth (coordinating whole body & development with environment, day to day physiology. Long range vs. short range communication (animal cells) Long range: ligand receptor, diffusing in and out to find target cell. Short range: diffusion, directly to find target cell. Pathway: signaling molecule synthesized & released by signaling cell, signal molecule travels to target cell, signal binds to receptor protein on/in target cell = transduction, change in protein activation/inactivation = change in gene expression = change in shape/movement. Decreased rate of firing (heart pacemaker cell) Can be slow (gene transcription and regulators) Can be predicted by chemistry of the signal molecule: cell-surface receptors: hydrophilic (charged proteins, intracellular receptors: hydrophobic (steroid, hormones) Steroids: small hydrophobic signal molecule entering cell to regulate gene transcription. Hormone steroid mechanism of action: ligand transcription factor/receptor activated in presence of hormone, activated receptor-hormone complex moves into nucleus, activated complex binds to regulatory region of gene & activates transcription.
