This thesis examines the impact of cobalt and chromium ions on the yeast Saccharomyces cerevisiae. The study focuses on the inhibitory effects of these heavy metals on yeast growth. It shows that as cobalt concentrations increase, the yeast's growth significantly decreases, as reflected by a notable drop in absorbance. This suggests that while cobalt is essential for yeast growth at lower concentrations, higher levels exhibit toxicity. Similarly, chromium ions also demonstrate a considerable negative impact on the yeast's growth. The decline in growth was evident even at relatively low chromium concentrations, emphasizing its toxicity. These findings highlight the significant inhibitory effects of cobalt and chromium on yeast growth, which is crucial for biotechnological applications involving Saccharomyces cerevisiae, especially in environments contaminated with these metals.