Pharmaceuticals, plastics, and other industries use enzymes to help synthesize molecular feedstocks. Enzymes taken straight from microbes such as bacteria are often not optimal for industrial use; one issue is that they often do not survive the elevated temperatures that speed up a synthesis. Genetic engineering can help tailor enzymes for these purposes. Knowledge of the exact atom-by-atom structure of the original enzyme is important in understanding enzyme function in nature, thus providing insight as to how to optimize the genetic engineering of enzymes. However, X-ray crystallography, a common technique for determining an enzyme's structure as a critical step in this process, can unfortunately alter its structure as well.