Here’s the Q cycle, an important redox loop and function of complex III in mitochondria. The Q cycle is part of the mitochondrial electron transport chain and transports electrons from reduced ubiquinone QH2 to cytochrome c via a Rieske iron-sulphur protein. It’s also important in setting up a proton gradient across the inner membrane - while the Qo site aims to oxidise QH2 to Q, the Qi site actually reduces Q to QH2. Qo electrons alternate between reducing cyt c and Q (or ubisemiquinone QH·). Since the ubiquinone can accept up to two electrons, the steps 3 and 4 are essentially the same as steps 1 and 2. Directionality is governed by the redox potentials of the various carriers and probably by the fact that reduced Rieske Fe·S protein takes a different conformation to the oxidised form.
The psychedelic mandala you are gazing at is a convergent beam electron diffraction pattern.
Electron diffraction refers to the wave nature of electrons. However, from a technical or practical point of view, it may be regarded as a technique used to study matter by firing electrons at a sample and observing the resulting interference pattern. This phenomenon is commonly known as the wave-particle duality, which states that the behavior of a particle of matter (in this case the incident electron) can be described by a wave. For this reason, an electron can be regarded as a wave much like sound or water waves. This technique is similar to X-ray and neutron diffraction.
Electron diffraction is most frequently used in solid state physics and chemistry to study the crystal structure of solids.
New measurements of the electron have confirmed, to the smallest precision attainable, that it has a perfect roundness. This may sounds nice for the little electron, but to one of the big physics theories beyond the standard model, it’s very bad news. Read more