BIOL 3113 Lecture Notes - Lecture 2: Electron Microscope, Cell Theory, Enzyme
Document Summary
In class slides that this pretyped notes did not have: microscopy started in 1665 1838 schleiden and schwann discovered cell theory. Three factors affect the quality of an optical image: magnification increase in the relative size of the image of an object, resolution the smallest objects that can be distinguished as a separate objects. Smaller distance better resolution: contrast the degree to which the image of an object stands out from its background. Microscope: based on the interaction of visible light and tissue components, based on the interaction of electrons and tissue components. Use to study the structure of cells and tissues. Light microscrope- use light = frequency to determine the light. *green light=500* r = 0. 61 n sin . N. a. =1. 41 (oil immersion lens) r = 0. 61 x 500nm r = 220nm = 0. 2 m. N. a. = 0. 01 (vacuum) r = 0. 61 0. 05nm r = 3nm = 0. 003 m. Preparation of tissues for microscopy - several steps required.
