. Elementary biophysics: selected topics . Fig. 49. Drawing of a model of the myoglobin molecule. The model shows the shape of the chain seen at 6 A resolution. The dark disc-shaped region is the haem group. putable in a straightforward way. Thus if the structure of the molecule being studied is either known or suspected, the pattern can be computed and compared with the experimental pattern. A skilled worker can use the comparison to make reasonable guesses about what modifications may be needed to make the theoretical pattern agree better with the observed pattern. Thus, by a series of trial
. Elementary biophysics: selected topics . Fig. 49. Drawing of a model of the myoglobin molecule. The model shows the shape of the chain seen at 6 A resolution. The dark disc-shaped region is the haem group. putable in a straightforward way. Thus if the structure of the molecule being studied is either known or suspected, the pattern can be computed and compared with the experimental pattern. A skilled worker can use the comparison to make reasonable guesses about what modifications may be needed to make the theoretical pattern agree better with the observed pattern. Thus, by a series of trial and error modifications, it is frequently possible to obtain a structure which fits the data very well. The phase problem still exists, but known bond lengths and angles and auxiliary information from infrared spectroscopy and other chemical means can frequently decide uniquely among alternatives. Through various clever stratagems and much hard work, the structures of several complex molecules of biological interest have been obtained in recent years. One of these is sketched in Fig. 49. The number of molecules whose structures have been determined is too small for any generalizations about three-dimensional structures to have emerged. But despite the complexities and the time needed for such x-ray diffraction studies of molecular architecture, there is rapidly increasing interest in these methods because at present the information can be obtained in no other way.
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Keywords: ., bookcentury1900, bookcollectionbiodiversi, booksubjectbiophysics
