BISC207 Lecture Notes - Lecture 3: Scanning Electron Microscope, Antonie Van Leeuwenhoek, Transmission Electron Microscopy

• School: University of Delaware
• Department: Biological Sciences
• Course: BISC207
• Professor: Victor Fomin

Document Summary

Cells are the fundamental system of biology, as the atom is to chemistry. Biologists use microscopes and the tools of biochemistry to study cells. Microscopes were invented in 1590 and refined in the 1600s. Robert hooke the first to view cell walls in 1665. Antoni van leeuwenhoek crafted lenses that allowed living cells to be observed. Light microscope an optical instrument with lenses that refract (bend) visible light to magnify images of specimens. Organelles any of several kinds of membrane-enclosed structures with specialized functions within eukaryotic cells. Electron microscope focuses a beam of electrons through the specimen or onto its surface: introduced in the 1950s. Scanning electron microscope uses an electron beam to scan the surface of a sample, coated with metal atoms, to study details of its topography. Transmission electron microscope used to study the internal structure of cells, an electron beam is aimed through a thin section of the specimen. Cytology the study of cellular structure.