BIOL 1090 Lecture Notes - Lecture 13: Transmission Electron Microscopy, Scanning Electron Microscope, Nuclear Membrane

• School: University of Guelph
• Department: Biology
• Course: BIOL 1090
• Professor: Jaideep Mathur

Document Summary

The cell is the structural unit of lice. All organisms are composed 1 or more cell types. Cells can arise only by the division of a pre-existing cell. Lms can magnify effectively to about 1000 times the size of the actual specimen. Visible light passes through a specimen and then through glass lenses, which magnify the image. Various techniques enhance contrast and enable cell components to be stained or labeled. Most subcellular structures, including organelles (membrane enclosed, compartments), are too small to resolve by a lm. Two basic types of electron microscopes (ems) are used to study subcellular structures. Scanning electron microscope (sems) focus beam of electrons onto the surface of a specimen, providing images that look 3-d. Transmission electron microscope (tems) focus a beam of electrons through a specimen. Tems are used mainly to study internal structures of cell. Carry out many chemical reactions enzymes. Dna in an unbound region called nucleoid.