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Structure of cog at the hub of metabolism reveals anti-ageing function

The structure of a key energy-releasing enzyme found in all animals is designed to minimise free radical production, an international team of researchers has reported in the journal Science. In a startling feat of structural biology, the team visualised the entire molecular structure of succinate dehydrogenase in the bacterium E. coli, allowing them to see for the first time how the protein’s three-dimensional shape helps prevent the formation of large quantities of these destructive oxygen atoms.

Image shows Mars glows in X-rays

This image from the Chandra X-ray Observatory has given scientists their first look at X-rays from Mars. In the sparse upper atmosphere of Mars, about 75 miles above its surface, the observed X-rays are produced by fluorescent radiation from oxygen atoms. X-rays from the Sun impact oxygen atoms, knock electrons out of the inner parts of their electron clouds, and excite the atoms to a higher energy level in the process. The atoms almost immediately return to their lower energy state and may emit a fluorescent X-ray in this process with an energy characteristic of the atom involved ? oxygen in this case. A similar process involving ultraviolet light produces the visible light from fluorescent lamps.