We conducted this experiment to determine if temperature affects the carbon dioxide production in yeast under aerobic conditions. Yeast, specifically baker’s yeast, is an organism used in baking that acts as the leavening agent that allows the dough to rise. Yeast is also single-celled fungi, this species of yeast is very strong and capable of fermentation. We hypothesized that higher levels of carbon dioxide will be produced in yeast with higher temperatures because chemical reactions occur faster at higher temperatures and will be faster than in cold temperatures. For this experiment, we conducted five trials at different temperatures to determine how much carbon dioxide was being produced at each temperature. The temperatures we tested were hot, cold, and room temperature. We placed the yeast solution in a small respiration chamber and measured carbon dioxide production with a CO2 probe. Our data did not suggest that higher temperatures will produce higher levels of carbon dioxide produced in yeast because the warmer temperature started to cause cell death within the yeast. Based on our results, our hypothesis was not supported and showed that room temperature is optimum for yeast.