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Essay On The Effect Of Concentration On Yeast Fermentation

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Design: 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 …show more content…

3. Weighing boat and scales were used to measure up 10 g of sugar, which was poured into flask “0%”. 4. Weighing boat and scales were used to measure up 10 g of yeast, which was added to flask with sugar. 5. Measuring cylinder was used to measure up 80 cm3 of tap water, which was added to flask containing sugar and yeast. 6. Contents of flask were stirred using stirring rod. 7. Flask and delivery tube with plug were set up in a water bath of 37-40°C with a clamp-stand (according to Fig. 1). 8. Measuring cylinder was filled completely with water and turned upside-down in bucket, over delivery tube (according to Fig. 1). 9. Stopwatch was started. 10. After 10 minutes, volume of gas collected in measuring cylinder was recorded. 11. Apparatus was rinsed. 12. Steps 2-3 were repeated using flask “1%”. 13. Measuring cylinder was used to measure up 79 cm3 of tap water, which was added to flask containing sugar and yeast. 14. Weighing boat and scales were used to measure up 1 g of table salt, which was added to flask containing sugar, yeast and water. 15. Steps 6-11 were repeated. 16. Steps 12-15 were repeated for the remaining salt concentrations (flask “5%” contained 5% salt, i.e. 5 g salt and 75 cm3 of water; flask “10%” contained 10% salt, i.e. 10 g salt and 70 cm3 of water, and so on). 17. Steps 1-15 were repeated five times. 18. Apparatus was cleaned

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