Rate of Respiration in Yeast

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Rate of Respiration in Yeast Aim: I am going to investigate the rate of respiration of yeast cells in the presence of two different sugar solutions: glucose, sucrose. I will examine the two solutions seeing which one makes the yeast respire faster. I will be able to tell which sugar solution is faster at making the yeast respire by counting the number of bubbles passed through 20cm of water after the yeast and glucose solutions have been mixed. Prediction: I predict that the glucose solution will provide the yeast with a better medium by which it will produce a faster rate of respiration. This is because glucose is the simplest type of carbohydrate (monosaccharide). However sucrose is a complex sugar it contains large molecules making it a disaccharide. Due to the large molecules being saturated and the small molecules being unsaturated this will allow the glucose to mix easily with the yeast therefore making it respire more frequently. The sucrose sugar however having larger molecules will find it harder to mix in with the yeast; this will make the rate of respiration in the sucrose much slower as it is not as efficient as the glucose. Yeast requires enzymes to digest the food on which the yeast is living. The enzymes digest the food the yeast is living on (normally sugars such as Glucose and Sucrose) breaking down the large molecules into smaller ones. It takes longer to break down the large molecules rather than the smaller molecules. This means that the yeast does not need to do any work when provided with small molecule foods such as glucose. The small molecule foods allow the yeast to respire easily. By already h... ... middle of paper ... ... improved in any way unless another sugar was utilized. There were some things that were difficult to keep constant in the experiment and this is where my results may have wavered slightly. It was difficult to keep the temperature of the warm water constant as it dipped at times which could have had an effect on how efficient the enzymes were. The delivery tubes were becoming blocked sometimes and by shaking the test tube it cleared them. However as we shook the test tube a large number of bubbles were formed which may not have formed if we didn't shake the test tube. Also we might have been shaking the test tubes at different speed which may have caused a greater number of bubbles to be released. Overall I felt that the experiment was accurate and reliable and there was not much that could have been changed on it.

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