BIO270H1 Lecture Notes - Lecture 4: Endocrine Gland, Paracrine Signalling, Cell Surface Receptor
Document Summary
Cell signaling: communication between cells, produce messenger -> releases messenger -> activates response. Types of cell signaling: direct signaling: cytoplasm connecting: used for small molecules. Moves through a hemi channel: 6 connexins. Indirect signaling: signaling cell releases chemical messenger, messenger is carried through ecf, communication of signal to target cell. Indirect signaling: short and long distance: short. Chemical messenger diffuses back to the signalling. Chemical messenger (hormone) transported by circulatory system. Electrical signal travels along a neuro and chemical messenger (neurotransmitter) is released. Across a synapse: exocrine: released to external environment (digestive tract); secreted through acinus, endocrine: released to internal environment; ductless gland. Chemical messengers: peptide, steroids, amines, lipids, purines, gases, bold known hormones, structure of chemical messenger (hydrophilic vs. hydrophobic) Peptide/ protein hormones: 2-200 a. a long, hydrophilic can travel in ecf, bind to receptors, rapid effects on cells, protein-protein phosphorylation.
