Cytology is the study of cell structure
Cell is the simplest collection of matter that can live
Hooke discovered "cells"
Schleidan "all plants are composed of living cells"
Schwann "all animals are made of living cells"
Virchow "existing cells give rise to new cells"
Cell Theory
"All organisms are composed of one or more living cells"
"Cell is the most basic unit of function"
"All cells come from existing cells"
Light microscope (Leeuwenhoek- first to view living cell and sperm) no finer than 0.2 micrometer
* Visible light pass through specimen-lenses-(light refracts)-projected into eye, film, video screen
Cell ultrastructure- a cell's anatomy as revealed by an electron microscope
EMs have shorter wavelengths than the wavelengths of visible light
ScanningEM- surface coated with a film of gold, topography of the specimen, depth of field, 3-D
TransmissionEM- internal, electron beam through specimen, electromagnets used to magnify and focus
Resolution- measure of the clarity of the image; the minimum distance two points can be separated
Magnification- apparent increase in object size; ratio of an object's image to its real size
Cell fractionation
* Enables a researcher to prepare specific components of cells in bulk quantity in order to study their composition and functions
* Process of taking cells apart, separating the major organelles so that their functions can be studied
* Centrifuge spins it at various speeds; ultracentrifuges spin at 130,000 rpm
* Homogenization is the disruption of cells; pellets (heavier) at the bottom; supernatants on top
* The supernatant is transferred to another tube and centrifuged again at a higher level
* Mitochondria are the sites of cellular respiration
All cells are bounded by the plasma membrane (selectively permeable with protein channels)
* Cytosol is a semi-fluid substance in which organelles are found
* Cytoplasm is the entire region between the nucleus...
English: Diagram of a cell showing the relative si...
Nucleus ER golgi ex
Transmission electron microscope image of a thin s...