• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

My aim is to discover how temperature effects the production of oxygen from yeast and hydrogen peroxide. I will mix yeast with hydrogen peroxide and use an upturned measuring cylinder to measure how much oxygen is produced.

Extracts from this document...

Introduction

Planning Aim My aim is to discover how temperature effects the production of oxygen from yeast and hydrogen peroxide. I will mix yeast with hydrogen peroxide and use an upturned measuring cylinder to measure how much oxygen is produced. To find out how much hydrogen peroxide and yeast I will use, I will carry out pre-tests. This will also aid accuracy of the final experiment by uncovering potential flaws in the method. Hypothesis and Theory There are many ideas to suggest that the change in temperature will cause an increase of respiration in yeast. Yeast is a single cell fungus made up mostly of protein, which has been use for its applications in fermentation. Yeast, after activation creates the ferments carbon dioxide and ethyl alcohol by secreting the enzyme zymase (a complex of 12 enzymes) in the yeast, which acts on simple sugars such as glucose. The alcohol produced has been used in making wines and bears and the carbon dioxide produced has been used in baking as it gets trapped in the dough and causes it to rise. Enzymes are catalysts which speed up reactions, they are made from protein and are specific as to which substrate they work on. Enzymes basically work due to the lock and key theory, where the substrate substance (the key) fits into the active site on the enzyme and they bind together, the reaction takes place and the substrate unlocks to form one or more substances leaving the enzyme ready to perform the binding again. ...read more.

Middle

1 2 2 6 3 11 4 13 Test 2 Time (minutes) Oxygen Produced (cm3) 1 2.5 2 6 3 10 4 12 Temperature: 29�C Test 1 Time (minutes) Oxygen Produced (cm3) 1 4 2 12 3 13 4 13 Test 2 Time (minutes) Oxygen Produced (cm3) 1 6 2 8 3 12 4 13 Temperature: 39�C Test 1 Time (minutes) Oxygen Produced (cm3) 1 9 2 11 3 12 4 15 Test 2 Time (minutes) Oxygen Produced (cm3) 1 8 2 12 3 14 4 15 Temperature: 48�C Test 1 Time (minutes) Oxygen Produced (cm3) 1 7 2 11 3 13 4 13 Test 2 Time (minutes) Oxygen Produced (cm3) 1 7 2 11 3 13 4 14 Temperature: 59�C Test 1 Time (minutes) Oxygen Produced (cm3) 1 16 2 19 3 21 4 21 Test 2 Time (minutes) Oxygen Produced (cm3) 1 17 2 20 3 21 4 22 I have ensured that my results are as accurate as possible by controlling all the variables stated in my planning section. I also took care when using the equipment so as to retain continuity throughout the experiment. For this, I checked everything was set up correctly at each reading and prepared my solution in the same way. I did not prepare a batch of solutions as this would have given some more time to acclimatise and more time to react and respire, changing the conditions. AVERAGES Temperature: 29�C Time (minutes) Oxygen Produced (cm3) 1 2.25 2 6 3 10.5 4 12.5 Temperature: 39�C Time (minutes) ...read more.

Conclusion

This would mean the temperature is not affecting the temperature. All three of these could make the experiment inaccurate. To make sure that the results were as reliable as I could make them, I calculated the mean of two results at each interval when dealing with the rate. The obvious anomalous result is at 3 minutes with temperature 39C, this could be due to the afore mentioned flaws in the method. I took all possible precautions to make the apparatus used to be reliable and give good values do I think the slight unreliability was caused by the preparation of the solution and the unpredictability of how the reaction went that came with it. To obtain more reliable results I would want complete continuity with preparations, maybe arranging sets of substances to create multiple solutions beforehand or preparing them but not actually activating the yeast so as to prevent any getting a head start over the others. This would ensure that all the preparations are the same and would give continuity. This would help give more reliable results throughout. If I were to further investigate this experiment and my results, I would probably want to calculate the point where the enzymes begin to denature for respiration in yeast. I could also examine the change in rate between the intervals to determine validity and continuity, also running them through maybe more intricate calculations involving log. At this stage, I shouldn't think there is too much more I can do. I think it would be interesting to vary the amount of H2O2 as an extension. Nikki Newland 11R ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Molecules & Cells section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Molecules & Cells essays

  1. Marked by a teacher

    Investigating respiration of maggots

    5 star(s)

    Like pyruvate, this is then decarboxylated and dehydrogenated in several steps, and eventually oxaloacetate is regenerated to allow the cycle to start again. Each turn of the cycle results in 2 carbon dioxide molecules forming, one FAD molecule and 3 NAD molecules are reduced and one ATP molecule is generated.

  2. Marked by a teacher

    The Effect Of Temperature on the Respiration Of Yeast.

    5 star(s)

    The bonds within a single substrate may be put under stress so that it is broken down. The reactions then form a product(s) and then leave the active site leaving it free to react with another substrate molecule. From the AS level I found out that PH, Substrate concentration Enzyme concentration and Temperature are all factor that effect enzymes.

  1. Investigation to find the effect of glucose concentration on fermentation of yeast.

    In the absence of oxygen, yeast will switch to an alternative pathway that does not require oxygen. The end products of this pathway are CO2 and ethanol. The first pathway yields a lot more energy per sugar molecule consumed, and so it is the "preferred" pathway if oxygen is present.

  2. Experiment to Show the Respiration Rate in Yeast

    This would help me to find the precise optimum heat capacity of the enzymes. Also if I wanted more accurate results of the temperatures used in this experiment, I could repeat everything but do each temperature five times instead of three. This would give an even more precise average.

  1. Investigating the Effect of Temperature on the Fermentation of Yeast

    length of collection time * the range of temperatures For the range, it was obvious that I wanted as many results as possible in the fairly short time limit, but I also wanted them over a large temperature range to fully investigate the effect of temperature.

  2. The rate of respiration in yeast and how it is affected by temperature.

    At 40 deg the amount of collisions are reaching the optimum high as it took a mean of 24.25 seconds to respire 1 ml of carbon dioxide. At 45 deg the rate of respiration is at the optimum high as it took 21.40 seconds to respire 1 ml of carbon dioxide.

  1. To investigate the rate at which hydrogen peroxide is broken down by the enzyme ...

    which is why the reaction speeds up when the concentration of the enzyme is increased. Therefore the more collisions that take place, the more oxygen that is produced, in a shorter quantity of time. I have also managed to obtain a predicted graph for different levels of concentration that can be used to affect the rate of reaction.

  2. Investigation into the Effect of Temperature on the Rate of Fermentation by Yeast.

    4. Every 30 seconds, the volume of CO2 in the gas syringe was recorded. 5. The experiment continued for 20 minutes. 6. The results were recorded in Tables 2-6. Fig 2. Results Temperature / oC Original volume in gas syringe / cm3 0 1.5 15 1 30 1 45 4 60 4 Table 1.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work