Examples of electron beam in the following topics:
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- Electron microscopy uses magnetic coils to direct a beam of electrons from a tungsten filament through a specimen and onto a monitor.
- Electron microscopy uses a beam of electrons as an energy source.
- An electron beam has an exceptionally short wavelength and can hit most objects in its path, increasing the resolution of the final image captured.
- The electron beam is designed to travel in a vacuum to limit interference by air molecules.
- The densely coated parts of the specimen deflect the electron beam and both dark and light areas show up on the image.
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- Electron beam processing is also commonly used for sterilization.
- Electron beams use an on-off technology and provide a much higher dosing rate than gamma or x-rays.
- A limitation is that electron beams are less penetrating than either gamma or x-rays.
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- Scanned-probe microscopy uses a fine probe rather than a light-beam or electrons to scan the surface of a specimen and produce a 3D image.
- SPM employs a delicate probe to scan the surface of the specimen, eliminating the limitations that are found in electron and light microscopy.
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- It is thus based on measuring the differences in refractive index upon recombining the two beams.
- Interference occurs when a light beam is retarded or advanced relative to the other.
- The microscope is a bright field light microscope with the addition of the following elements: a polarizer between the light source and the condenser, a DIC beam-splitting prism, a DIC beam-combining prism, and an analyzer .
- Manipulating the prism changes the beam separation, which alters the contrast of the image.
- Two parallel light beams pass through the specimen and combine to produce an image.
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- Sulfur-oxidizing organisms generate reducing power for carbon dioxide fixation via the Calvin cycle using reverse electron flow—an energy-requiring process that pushes the electrons against their thermodynamic gradient to produce NADH.
- In all cases the energy liberated is transferred to the electron transport chain for ATP and NADH production.
- Thiobacillus denitrificans) use nitrate (NO−3) as a terminal electron acceptor and therefore grow anaerobically.
- In this metabolic process, internal stored nitrate is the electron acceptor and reduced to ammonia.
- The red dots are range-finding laser beams.
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- In anaerobic respiration, a molecule other than oxygen is used as the terminal electron acceptor in the electron transport chain.
- This method still incorporates the respiratory electron transport chain, but without using oxygen as the terminal electron acceptor .
- Many different types of electron acceptors may be used for anaerobic respiration.
- Acetogenesis is a type of microbial metabolism that uses hydrogen (H2) as an electron donor and carbon dioxide (CO2) as an electron acceptor to produce acetate, the same electron donors and acceptors used in methanogenesis.
- Organic compounds may also be used as electron acceptors in anaerobic respiration.
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- Electrons can enter the electron transport chain at three levels: dehydrogenase, the quinone pool, or a mobile cytochromeelectron carrier.
- In prokaryotes (bacteria and archaea there are several different electron donors and several different electron acceptors.
- Note that electrons can enter the chain at three levels: at the level of a dehydrogenase , at the level of the quinone pool, or at the level of a mobile cytochrome electron carrier.
- NADH is the electron donor and O2 is the electron acceptor.
- Bacterial electron transport pathways are, in general, inducible.
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- Chemolithotrophs use electron donors oxidized in the cell, and channel electrons into respiratory chains, producing ATP.
- Chemotrophs are organisms that obtain energy through the oxidation of electron donors in their environments.
- In chemolithotrophs, the compounds - the electron donors - are oxidized in the cell, and the electrons are channeled into respiratory chains, ultimately producing ATP.
- The electron acceptor can be oxygen (in aerobic bacteria), but a variety of other electron acceptors, organic and inorganic, are also used by various species.
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- In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule to another.
- In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule, the reductant, also called the electron donor, to another the oxidant, also called the electron acceptor.
- In this example, A is the reductant (electron donor) and B is the oxidant (electron acceptor).
- In this reaction, NAD+ is the oxidant (electron acceptor) and glyceraldehyde-3-phosphate is the reductant (electron donor).
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- Water is therefore not used as an electron donor.
- This restricts them to cyclic electron flow and are therefore unable to produce O2 from the oxidization of H2O.
- The cyclic nature of the electron flow is typified in purple non-sulfur bacteria.
- Excited P870 will then donate an electron to Bacteriopheophytin, which then passes it on to a series of electron carriers down the electron chain.
- Therefore electrons are not left over to oxidize H2O into O2.