BIOL 121 Lecture Notes - Lecture 10: Receptor Antagonist, Activation Energy, Membrane Potential
Document Summary
To communicate with one another, cells release chemical messengers (ligands) Cells only respond to messengers if they have the correct receptor (chemical specificity) Ligand binding to a receptor that triggers a cellular response. Decrease in # of receptors- down regulation. Due to chronic, high levels of the ligand. Increase in # of receptors- up regulation. Due to chronic, low levels of the matching chemical messenger. Can be from signal from separate chemical messenger. Binds to receptor and elicits a response and doesn"t elicit a response. Receptor binding is the just the switch, what happens after, depends upon the signal transduction pathway. Receptor binding and activation can lead to. Change in permeability, transport properties, or electrical state of a cell membrane. Transduction pathways differ between lipid-soluble messengers and water-soluble messengers. Ligand bind intracellular (can pass through the cell membrane) (non polar) Ligand binds to extracellular portion of plasma membrane receptors (cant pass through membrane) (polar)