BIO 1140 Lecture Notes - Lecture 1: Scanning Electron Microscope, Antonie Van Leeuwenhoek, Transmission Electron Microscopy
9 Feb 2018
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Topic #1: introduction of cell biology and features. Cell walls were first viewed by robert hooke in 1665 as he looked through a microscope at dead cells from the bark of an oak tree. It was antoni van leeuwenhoek who in 1674 visualize living cells. Light microscopy (lm): visible light is passed through the specimen and then through a glass lenses which refract (bend) the light in such a way that the image is magnified and projected into the eye or a camera. The important parameters in microscopy are magnification, resolution, and contrast. Magnification: the ratio of an object"s image size to it"s real size. Resolution: is a measure of the clarity of an image; it is the minimum distance two points can be separated and still be distinguished as separate points. Contrast: the difference in brightness between the light and dark areas of an image. Organelles: membrane enclosed structures within eukaryotic cells.
