BIOMG 1350 Lecture Notes - Lecture 2: Transmission Electron Microscopy, Theodor Schwann, Electron Microscope
29 Aug 2016
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Cells first described in 17th century: robert hooke. 1655 paper that described and showed structure of cork saw rectangular spaces in rows, actually cell walls coined the term cell : antonie van leeunwenhook (1632-1723) First person to observe individual living cells, bacteria specifically. Cell theory (1838) cells are universal building blocks of all living tissues: matthias shcleiden & theodor schwann. Drawings of cells by dr. schwann in microscopic investigations on the. Accordance in the structure and growth of plants and animals: all living organisms are composed of one or more cells, the cell is the most basic unit of life, all cells arise only from pre-existing cells. Resolving power: the ability to distinguish two close objects, maximum resolving power of a microscope depends on the wavelength of the illumination. Visible light has wavelengths of 400-700 nm and can resolve objects about 200 nm apart. In a 200 kv electron microscope, the wavelength of the electrons is 2. 5 pm.
