Description_x000D_ Application_x000D_ Ferredoxin has been used in studies of assimilation of inorganic nitrogen from nitrite or nitrate in the absence of ammonium. Ferredoxin is important in the electron transfer cascade required for this nitrogen assimilation._x000D_ Biochem/physiol Actions_x000D_ Ferredoxins are iron-containing proteins that serve as electron-transfer catalysts in photosynthesis and nitrogen fixation._x000D_ Packaging_x000D_ Package sizes are based on ferredoxin content._x000D_ Preparation Note_x000D_ Partially purified by the method of Tagawa and Arnon, Nature, 195, 537 (1962).