a microscope that uses a beam of electrons as a radiation source for viewing the specimen. The resolving power (ability to register fine detail) is a thousand times greater than that of an ordinary light microscope. The specimen must be examined in a vacuum, which necessitates special techniques for preparing it, and the electrons are usually focused onto a fluorescent screen (for direct viewing) or onto a photographic plate (for a photograph, or electron micrograph). A transmission electron microscope is used to examine thin sections at high magnification. A scanning electron microscope reveals the surfaces of objects at various magnifications; its great depth of focus is advantageous.
An optical instrument comprising adjustable magnifying lenses that greatly enlarge a small object under study – for example, an insect, blood cells, or bacteria. Some microscopes use electron beams to magnify minute objects such as chromosomes, crystals, or even large molecules. Optical microscopes are also used for MICROSURGERY when the area being operated on is otherwise inaccessible: for example, in eye and inner ear surgery; for the removal of tumours from the brain or spinal cord; and for resuturing damaged blood vessels and nerves.... microscope
A binocular MICROSCOPE used for MICROSURGERY on, for example, the EYE and middle EAR; this microscope is also used for suturing nerves and blood vessels damaged or severed by trauma and for rejoining obstructed FALLOPIAN TUBES in the treatment of INFERTILITY in women.... operating microscope
a series of enzymes and proteins in living cells through which electrons are transferred, via a series of oxidation-reduction reactions. This ultimately leads to the conversion of chemical energy into a readily usable and storable form. The most important electron transport chain is the respiratory chain, present in mitochondria and functioning in cellular respiration.... electron transport chain
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