Cellular Respiration

778 WordsSep 15, 20134 Pages
Abstract The effect of nature of substrates on the rate of cellular respiration in yeast was determined by using the Smith fermentation tube method. Mixtures of 15ml distilled H2O, 10% yeast suspension and 15ml of the following solutions (all at 10% concentration):1- starch, 2 – lactose, 3 – sucrose, 4 – glucose, 5 – fructose, 6 – distilled water , were poured in six smith fermentation tubes. Cotton balls were plugged in the openings of the tubes and the tubes were kept upright and observed for 30 minutes. The mixture with the sucrose solution acquired the highest computed volume of gas evolved and the rate of CO2 evolution seconded by glucose and followed by fructose. This stated that the higher the amount of the CO2 evolved, the faster…show more content…
The mixtures were shaked gently and assured to have no bubbles trapped at the closed end. If there were bubbles, it will be removed by covering the opening with the palm of one hand and tilting the tube horizontally. The openings of the tubes were plugged with cotton balls. The tubes were tied together at their vertical arms to keep them upright and were set aside where the will not be disturbed. All CO2 evolved will be trapped in the vertical arm and the height of the area occupied by the CO2 evolved were measured every five minutes for thirty minutes. The volume of the gas evolved and the rate of CO2 evolution were computed. The rate of CO2 evolution was computed by the amount of CO2 evolved over time and the volume of the gas evolved was computed by the formula: Volume = pir2h whereas pi= 3.14 r= radius of the smith fermentation tube (cm) h= height of the area occupied by the CO2 evolved (cm) Computed results were tabulated. A graph of volume of CO2 evolved and time elapsed was then plotted and
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