Investigation of Fermentation free essay sample

Investigation of Fermentation Introduction Introduction Yeast (Saccharomyces)is a single-celled microorganism in the Fungi family. It anaerobically respires sugars to produce ATP, as well as the waste products ethanol and carbon dioxide gas. This process is known as fermentation. There are various factors that affect the rate at which yeast respires. Aim To investigate the effect of concentration of table salt (sodium chloride) on the rate of fermentation of sucrose using yeast, measured in the volume of carbon dioxide gas collected over a period of 10 minutes. Research question What is the effect of concentration of table salt on rate of fermentation? Hypothesis I predict that as salt concentration is increased, the rate of fermentation will decrease. Yeast cells do not have a cell wall and therefore, due to osmosis, a higher salt concentration outside the yeast cells will provide them with a hypertonic environment. This will cause water to move from the yeast cell to its surroundings, down the concentration gradient. We will write a custom essay sample on Investigation of Fermentation or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Thus the yeast cells will become dehydrated, cannot function properly and eventually die. Standard deviation should also be calculated to measure the spread of the data, using Excel or the formula (where s=standard deviation; x=each measured value of volume of CO2; and n=number of trials). The mean volume of CO2 versus concentration of salt should be plotted on a line graph, with standard deviation shown with Y-error bars. Safety Precautions Good laboratory practise, including appropriate clothing, is important in order to avoid hazards and risks. Water bath must not exceed 40Â °C, as high temperatures could cause burns.