HHP 3500 Lecture Notes - Lecture 4: Autocrine Signalling, Molecular Diffusion, Phospholipid
1 Sep 2016
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Document Summary
Special things about eukaryotic cells-nucleus, compartments (membranes) and has organelles. Plasma membrane: characteristics: surrounds cell and organelles cytoplasm-everything inside cell membrane except for nucleus (fluid+organelles) cytosol-intracellular fluid inside of cell membrane, but outside organelles (just fluid) Plasma membrane serves as selective barrier, so can regulate transport of things. It also contains sensors for chemical messengers: paracrine, hormone, autocrine, neurotransmitters. Prvides cellular support, anchors cells to adjacent cells and to extracellular matrix: structure: Transmembrane proteins-can form channels, and transmit electrical signals. Peripheral proteins- attached to inside or outside; functions-enzyme activity and also cell shape and motlility. Glycoproteins- proteins on cells that recognize as self : what holds cells together? serve in cell recognition. Desmosome-membranes of adjacent cells linked by cadherins sticking through cell membranes, then dense plaque that holds these cadherins together;strong junctions. Tight junctions- water proof seals; restricts molecular diffusion between cells. They prevent paracellular transit (no substance between cells), but allow transcellular pathways (move through cells)
