The Relationship Between Food Concentration, And Respiratory Activity :: essays research papers fc

The Relationship Between Food Concentration, and Respiratory ActivityIn this experiment different concentrations of sucrose were bear witnessed to determinewhich leads to the most respiratory activity in yeast. Yeast is a heterotrophicanaerobic fungus which lacks chlorophyll. Yeast is used commercially toferment the sugars of wheat, barley, and corn to produce alcohol, and in thebaking industry to raise or expand dough. Yeast or alcoholic fermentation isthe anaerobic process of respiration by which sugars, such as glucose andsucrose, are converted into ethanol and carbon dioxide (carbonic acid gas ). This process isillustrated in the following equationyeast C12H22O11 + H2O--- 4 CH3CH2OH + 4 CO2sucrose + water (yields) ethanol + carbon dioxideIn order to determine what concentration of sucrose and water leads tothe most respiratory activity, ten large demonstrate tubes were set with differentconcentrations by the process of serial dilution. The first test tube wasfilled with 40 ml of 60% sucrose solution. Then, the nine rest test tubeswere serially diluted, so that the sucrose concentration ranged from 30% to0.12%.The hypothesis in this expriment was that the most respiratory activitywould take place with 60% sucrose concentration. Since yeast fermentationrequires sucrose and water, aproximately equal proportions of both would yieldto the most respiratory activity.Once the sucrose concentration was serially cut to the desired level,the experimenter added 5 ml of yeast suspension to each one of the ten testtubes.Then, ten small test tubes were placed invertedly into each one of thelarge test tubes, making sure no air bubbles remained within the small tibes.The test tubes were left 24 hours, allowing for fermentation to takeplace. But, no respiratory activity was detected.In previous experimentation, it was found that yeast fermentation didtake place in different molasses concentrations. Since, molasses containslarge quantities of sucrose, it was assumed th at different concentrations of