MICR 2123 Final: Final Exam Study Guide
Document Summary
Know that microbial cells can range from a few nanometers to a fraction of a millimeter in size. Need microscopes to be able to see them. Microscopes increase resolution by increasing magnification: know the definitions. Light vs electron microscopy: light vs electron beams. Know all 4 examples of light microscopy: bright field resolution increases by fixation and staining, dark field objects are halos of light against dark background. Light scattering: phase contrast uses light refraction, fluorescence uses fluorophores. Know the examples of electron microscopy: sem (scanning) electrons scan the surface. Coat and scan: tem (transmission) electrons pass through the specimen. Coat and cut: know why we coat with heavy metals in electron microscopy. Cell model cytoplasm, cell membrane, cell wall, internal nucleoid, external structures (like flagella, pili, sex pili) Cell membrane semi-permeable only to a few small molecules: made of phospholipid bilayer and proteins.