BIOL 2021 Lecture Notes - Lecture 2: Amine, Micelle, Glycerol
14 Apr 2017
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2 types: tem (transmission em) needs thin slices of specimen (in sections) -> soak in stain -> add heavy metal (mag) Membrane made up of heavy metal: scanning em electrons scattered from surface. Still need to add heavy metal to specimen. Thin on surface -> stain only on surface. Membranes tend to be seen b/c heavy metals bind there alot: eg. With sem can only see outside of cell -> 3d surface picture. With tem can see inside of cell: staining is needed for em. Also needs heavy metal to scatter the electron or bounce off them. Without it electrons would just pass though specimen not creating an image: em uses electrons instead of light (photon beams) to view specimen. Blood vessels: what"s wrong with video shown. Its not closely packed (should be bumping into eachother) Things are moving as if they know where to go. David s. goodseel painting: green membrane, highly packed-> no room for water.
