Heavy metal assault in Saccharomyces cerevisiae results in increased oxidative stress, resulting in direct damage to proteins, lipid membranes and nucleic acids; even after relatively short (>1hr) exposures. Such effects are mitigated and potentially exacerbated by changes in intracellular metabolic pathways, causing a variety of responses. Synthesis and recycling of glutathione within the cell (a major metabolic cycle which minimizes oxidative stress) is especially influenced by exposure to heavy metals depending on the type. Redox active metals (copper and chromium (VI)), influence the oxidative stress of the cell by affecting GSH/GSSG pools, while the redox inactive metal (cadmium) appears to lead to a major increase in glutathione production. Supplementation of cells with mixed amino acids (FFAAP) provides an exogenous source of the building blocks for glutathione, has a recuperative effect on all cells, leading to a decrease in oxidative stress and a lowering of total glutathione and/or normalizing GSH/GSSG pools.