BIOL 102 Lecture Notes - Lecture 6: Transmission Electron Microscopy, Scanning Electron Microscope, Cell Fractionation
Document Summary
Cell theory: all organisms are made of cells and all cells have 4 common features and a common evolutionary ancestor light microscope: 2 nanometers; stains or dyes increase contrast so you can see nucleus but not smaller organelles. 2 kinds of electron microscopes for 1 nanometer or less. We can"t use em all the time because: Cells must be killed (must be sliced or covered in gold) Cell fractionation is also used to study cells. Centrifuges fractionate cells into their component parts. Prokaryotes: 3. 5 to 3. 8 billion years ago: they have no nucleus and belong to the domains bacteria and archaea. Eukaryotes 1. 9 to 2. 1 billion years ago: means true nucleus; belong to domain eukarya which includes protists, fungi, animals and plants. Plasma membrane phospholipids: protects cell because it is semi-permeable. Cytosol (semifluid substance that makes up cytoplasm): the goo inside. Chromosomes (carry genes, dna): heredity ribosomes (make proteins, rna): reads dna too. Has nucleoid, bacterial chromosome, ribosome, plasma membrane.
