BENG 140B Lecture Notes - Lecture 4: Membrane Transport Protein, Phosphodiesterase, Enzyme
Document Summary
Chapter 5: control of cells by chemical messengers = how hormones & other signals work. Communication requires: signals (ligands) and receptors (binding proteins) The chemical properties of a ligand predict its binding site: Hydrophobic/ lipid soluble: cytosolic or nuclear receptors. Receptors are proteins that can bind only specific ligands and they are linked to response systems. Hydrophobic signals typically change gene expression, leading to slow but sustained responses. Hydrophilic signals typically activate rapid, short-lived responses that can be of drastic impact. Receptors on the surface of a cell are typically proteins that span the membrane black beads are amino acids that go through phosphorylation. Only cell a has the matching receptors for this chemical messenger, so it is the only one that responds. Therefore, are not directly affected by the signal. This hydrophobic signal requires a carrier protein while in the plasma . But at the target cell the signal moves easily through the membrane and binds to its receptor.
