What causes moldy bread and foods? How can you stop it? If you understand what fermentation is and how yeast survive you can answer these questions. Fermentation is the conversion of pyruvic acid into other compounds such as lactic acid or ethyl alcohol. Fermentation occurs when cells do not have oxygen. Some Organisms that use fermentation are fungi and bacteria.
Yeast are a type of fungus that uses fermentation for cellular respiration. This experiment tests at what temperatures yeast can perform fermentation. If the temperature is freezing then fermentation will not occur. The Materials needed for this experiment are 40 The Materials needed for this experiment are 40 plastic bottles , 20 rubber tubes, 20 rubber bands, 2 100ml beakers, a 400ml beaker, a graduated cylinder,60ml of yeast, 300ml of water, a liter of Bromthymol Blue, and a liter of sucrose solution. Make 50ml of sucrose and yeast solution by adding a spoonful of yeast to 15ml of water in a flask, mix until dissolved. Add 50ml of sucrose solution to the flask and stir until mixed. Put 50ml of the final solution into a plastic bottle. In another bottle add 50ml of Bromthymol Blue and attach bottles together with a rubber tube at the openings and hold the bottles together with a rubber band. Repeat that process exactly 19 more times to make 20 pairs of bottles. Place 5 sets at room temperature, 5 in the Refrigerator, 5 in the freezer, and 5 in a Biochamber. At the end of 48 hours check if fermentation occurred by looking at the color of the solution in each set of bottles. If the solution is blue or green fermentation didn?t occur, if the solution is yellow fermentation occurred.
