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Investigate the effect different concentrations of glucose in a yeast & Glucose solution has on the rate of respiration in Yeast.

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GCSE Biology Coursework - Yeast Respiration Aim: To investigate the effect different concentrations of glucose in a yeast & Glucose solution has on the rate of respiration in Yeast. Introduction: Respiration is the process of converting glucose to energy, which goes on in every cell. The chemical formula is: Glucose + Oxygen ---> Energy + Water + Carbon Dioxide C6H12O + 6O2 --> Energy + 6H2O + 6CO2 Glucose --> Energy + Alcohol + Carbon Dioxide To measure the rate of respiration I will measure the rate of CO2 produced (a product of respiration) by measuring the volume produced in a certain time. Variables: This is an investigation into how the different concentrations of glucose have on respiration in yeast. In this investigation there will be many different factors that could affect the outcome of the experiment. The main one being yeast concentration, this will effect the experiment in the way that the more concentrated the yeast is, the quicker it will react with glucose. Another factor that plays a big part in the outcome of the experiment is the temperature. ...read more.


There is no guarantee though that my prediction will be right since there are different factors which could cause a change. Measuring the CO2: I will measure the amount of CO2 given off by using a burette rather than counting the bubbles given off. I will do this because it will allow for a higher degree of accuracy. To explain how this will be set up underneath is a diagram to explain. As the CO2 is produced it will bubble into the burette. An equivalent volume of water will be pushed out of the burette. Apparatus: * Clamp Stand * Bowl * Water * Yeast * Glucose * Stop watch * Measuring cylinder * Conical flask * Delivery Tube * Bung * Burette Concentrations: In this experiment I Will use 5 different concentrations of Glucose, and will retry twice for each, thus resulting in 15 different types of answers. I will then get an average for each concentration and plot them on a graph. The 5 different concentrations I will use are (Glucose cm3): * 90 * 80 * 70 * 60 * 50 * 30 To ensure that my results are reliable I will replicate the experiment 3 times for each ...read more.


The evidence I have I am not sure if they are accurate given the anomalous results. Evaluation: In this experiment I think there are many ways in which I could have improved the way in which it was conducted. The first being is using more advanced equipment, such as digital thermometers, freshly made up yeast and glucose, and a computer timing and recording the results. The second is making sure that each time that I preformed an experiment all the containers were cleaned and checked to make sure that the pH was around neutral and no heavy metals were present. Another way in which this experiment could have been improved is that results were recorded more than 3 times thus giving a more accurate set of results, also using more concentrations of yeast/water could give more accurate results. Additionally to help to perfect this experiment and get improved and more accurate results, I could do additional experiment, where I could use more glucose concentrations and use more time in which to record them, such as instead of doing minutes 1-5 I could do minutes 1-10 thus resulting in more accurate results. ...read more.

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