BIO 2110 Lecture Notes - Aldosterone, Catecholamine, Extracellular Fluid
Document Summary
Cellular communication everything an animal does involves communication between cells: example: moving, digesting food cell signaling: communication between cells, signaling cell sends a signal (usually chemical, target cell receives the signal and responds to it types. Indirect (more common) signaling cell releases chemical messenger chemical messenger carried in extracellular fluid: some may be excreted into environment chemical messenger binds to a receptor on target cell activation of signal transduction pathway response in target cell. Chemical messengers: peptides hydrophilic, soluble in aqueous solution, travel to target cell dissolved in extracellular fluid short half lives (seconds hours) need to be continuously produced bind to transmembrane receptors (ligand binding domain), conformation of receptor which causes change, signal transduction, alters membrane potential rapid effects on target cells (ex, growth factors, steroids derived from cholesterol three classes, mineralocorticoids regulate sodium uptake by kidney electrolyte balancing ex.