Oxygen Uptake by Saccharomyces cerevisiae

Place 5 ml of the yeast suspension in the sample chamber and repeat steps 1-41 to 1-45 inclusively. 

Allow the yeast to utilize about half the available oxygen. If for any reason stirring of the sample stops the trace will immediately drop towards zero, owing to oxygen depletion in the immediate vicinity of the electrode. If this occurs, simply restart the stirring process. 

Prepare castor bean mitochondria as described in steps 9-1 to 9-16. 1-62. Repeat step 1-48 using the mitochondrial resuspension medium in place of water. This medium (adjusted to pH 7.4 with HCl) is composed of 45 g mannitol, 6.05 g Tris, and 0.37 g EDTA per liter of solution. 

Calibrate the electrode and recorder assembly (steps 1-38 to 1-52 inclusively). 

Place 5 ml of the oxygen-saturated solution (prepared in step 1-62) in the sample chamber. 

---