BSC 2010C Chapter Notes - Chapter 6: Scanning Electron Microscope, Nuclear Membrane, Electron Microscope
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Biology 1: biologists use microscopes and the tools of biochemistry to study cells, microscopy a. i. Light microscope (lm): visible light passes through the specimen and then through the glass lenses; the lenses reflect (bend) the light so the image of the specimen is magnified a. ii. Organelles: the membrane- enclosed structures within eukaryotic cells a. iii. Electron microscope (em): rather than focusing light, it focuses a beam of electron through the specimen or onto its surface. a. iv. Scanning electron microscope (sem): especially useful for detailed study of the topography of a specimen a. v. All cells share certain basic features: bounded by a plasma membrane, inside all cells is a semifluid, jelly-like substance called cytosol, chromosomes, and ribosomes (tiny complexes that make proteins according to instructions from the genes) a. ii. Cytosol: jelly-like substance in which subcellular components are suspended a. iii. Eukaryotic cell: most of the dna is in an organelle called the nucleus, which is bounded by a double membrane a. iv.
