This document presents the results of a practical work on catalase activity in yeast cells, including the evolution of oxygen concentration and quantity released over time at different temperatures. The analysis provides insights into the functioning of catalase and its impact on oxygen production.
Extract
[...] Corrected practical work - Catalase Results: Figure 1 - Evolution of O2 concentration over time tube 1 tube 2(0°C) tube 3 (100°C) slope of the curve (dy/dx) / s / " - / s Tableau 1 - Oxygen quantity released over time Analysis: The evolution of the oxygen quantity released over time is similar when the yeast solution was left at room temperature or exposed for 15 minutes at a temperature of 0°C: it increases regularly, up to 0.55% additional oxygen per second. This evolution reflects the good functioning of the catalytic activity of catalase, present in yeast cells as in most living beings: the oxygen rate increases because the reaction of decomposition of hydrogen peroxide into water and oxygen is proceeding well. In contrast, the oxygen rate in the yeast solution exposed to a temperature of 100°C decreases slightly, to the tune of 0.01% less oxygen per second. [...]
[...] This evolution reflects the non-functioning of catalase: the reaction of decomposition of hydrogen peroxide does not occur, so there is no oxygen production. The slight decrease in oxygen rate during the first 150 seconds could be due to the respiration of yeast, before the cellular death caused by hydrogen peroxide, which would explain the stability of the oxygen rate after 150 seconds. [...]
