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During a NASA wind tunnel test, a model of the Space Shuttle is targeted by a beam of electrons, simulating the effect of ionizing gases during re-entry. [174] Electron beams are used in welding. [175] They allow energy densities up to 10 7 W·cm −2 across a narrow focus diameter of 0.1–1.3 mm and usually require no filler material. This ...
An electron transport chain (ETC [1]) is a series of protein complexes and other molecules which transfer electrons from electron donors to electron acceptors via redox reactions (both reduction and oxidation occurring simultaneously) and couples this electron transfer with the transfer of protons (H + ions) across a membrane.
These electron transfer reactions are the main function of NAD. It is also used in other cellular processes, most notably as a substrate of enzymes in adding or removing chemical groups to or from proteins, in posttranslational modifications.
Tests that use this reagent are called Benedict's tests. A positive result of Benedict's test is indicated by a color change from clear blue to brick-red with a precipitate. Generally, Benedict's test detects the presence of aldehyde groups, alpha-hydroxy-ketones, and hemiacetals, including those that occur in certain ketoses.
Positron emission tomography (PET) [1] is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, regional chemical composition, and absorption.
In structural biology, resolution can be broken down into 4 groups: (1) sub-atomic, when information about the electron density is obtained and quantum effects can be studied, (2) atomic, individual atoms are visible and an accurate three-dimensional model can be constructed, (3) helical, secondary structure, such as alpha helices and beta sheets; RNA helices (in ribosomes), (4) domain, no ...
In biochemistry, electron bifurcation (EB) refers to a system that enables an unfavorable transformation by coupling to a favorable transformation. Two electrons are involved: one flows to an acceptor with a "higher reduction potential and the other with a lower reduction potential" than the donor. [ 1 ]
Electron microscopy is known to swiftly decay biological samples compared to samples in materials science and physics due to radiation damage. [15] In most other electron microscopy-based methods for imaging biological samples, combining the signal from many different sample copies has been the general way of surpassing this problem ( e.g ...