Long description

Figure 11 Fe-EXAFS radial distribution plot of iron-containing ferritin. Notice that there are two peaks, the first at 160 pm corresponding to a sphere of oxygen atoms, and the second at 290 pm corresponding to a sphere of iron atoms. (The peak due to the iron atoms is smaller than the peak due to the oxygen atoms; this is not in accord with the relative number of electrons in oxygen and iron atoms, The reasons for this are complex, but involve other factors beside the number of electrons in the intensity of back-scatterring. Also the actual structure of the hydrated iron(III) oxide in ferritin is not ‘perfect’, in that there are incomplete ‘shells’ of iron atoms, and poor long-range crystal order.)