BIOL150 Chapter Notes -Dna-Binding Domain, Steroid Hormone Receptor, Adrenal Gland
Document Summary
When signal molecule binds receptor > cellular response. Changes in gene expression ? protein synthesis. Cells need to communicate with each other to coordinate, direct channels of communication. Any signal pathway has 3 stages: reception, transduction through signalling cascade, response. Reception by a cell surface receptor: signal molecules-neurotransmitters,hormones, Receptors: integral membrane glycoproteins responses usually rapid, short lived events. Surface receptors: integral proteins usually glycoproteins, specific fit, induces molecular change in the receptor that activates its cytoplasmic end. Receptors allow only correct ligands to bind and signal to a cell. Reception by a receptor within a cell: signal molecules-steroid hormones intracellular receptors: steroid hormone receptor, hormone binding domain& dna binding domain, responses occur over a longer time. Steroid hormones can pass through lipid bilayer, hormone binds to its receptor within cytoplasm, hormone receptor complex can enter nucleus and influence gene expression. Specific binding but the affinity is not strong enough. Kinase groups add phosphate to target molecules usually other proteins.