ABSTRACT
Iron’s ability to pass readily between the divalent and trivalent states is its most important biological property. The first biochemical study of iron metabolism in Saccharomyces cerevisiae was made by Elvehjem in 1931. S. cerevisiae is able to use a great variety of iron compounds present in extracellular media to fulfill its nutritional requirements. The rate of iron uptake by resting cells depends on several factors, including the way the cells were cultured and the conditions of the iron assay itself. Soluble cytosolic ferrireductase activities may participate in iron assimilation in many microorganisms and may account for the intracellular dissociation of siderophores. Trans–plasma membrane electron transfer in plant cells is accompanied by an increased efflux of protons. Several models have been proposed for the coupling between reductase activity and the accompanying pH changes. The yeast S. cerevisiae possesses a plasma membrane electron transport system that is far from simple.
