Angstrdm unit

Fig. 12.1. Types of hydrogen atoms. R can be C, N or O in a-d. See 12.2.2 Table 12.1. Atomic Radii Adopted (Angstrdm Units)...

The substrate molecule must fit exactly into the mosaic pattern of the enzyme surface. The combination is only possible if enzyme and substrate can approximate in such a way that the two hypothetical binding-planes are not more than a few Angstrdm units apart (Bergmann, 1937). Thus, pancreatic peptidase will not attack synthetic peptides made from the non-natural D-amino acids. 

Anders Jonas Angstrdm (1814-1874) became a doctor of physics in Uppsala in 1839 and professor in 1859. He carried out comprehensive pioneering work in spectral analysis. In 1868 he published a work on the sun s spectrum, a work that has been characterized as monumental. He gave there, to six significant figures, wavelengths for more than 1000 Fraunhofer lines. He used the wavelength unit 10 cm = 10 ° m. 

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