BIO 106 Lecture Notes - Electron Microscope, Lipid Bilayer, Ultrastructure
21 Jul 2022
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Document Summary
A variety of microscopes have been developed for a clearer view of cells and cellular. In a light microscope (lm), visible light passes through a specimen, then through glass lenses, and finally is projected into the viewer"s eye. Specimens can be magnified by up to 1,000 times. Magnification is the increase in an object"s image size compared with its actual size. Resolution is a measure of the clarity of an image. In other words, it is the ability of an instrument to show two nearby objects as separate. The human eye and the microscope have limits of resolution - the ability to distinguish between small structures. Therefore, the light microscope cannot provide the details of a small cell"s structure. In the 1800s, these studies led to cell theory, which states that: All living things are composed of cells. Beginning in the 1950s, scientists started using a very powerful microscope called the electron microscope (em) to view the ultrastructure of cells.
