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

Effect of different substrates on fermentation by Yeast.

Extracts from this document...

Introduction

Effect of Different Substrates on Fermentation by Yeast Background: Yeast respire anaerobicly Glucose � ethanol + CO2 ( + 2ATP ) Aim: To find the effect of different substrates on fermentation by yeast. Apparatus: Bunsen Burner Boss Safety Mat Trough Tripod Stop Clock Gauze Scales Beaker Boats Thermometer Matches 6 Test Tubes Pipette Bung Spatula Delivery Tube Oil Measuring cylinder Yeast Water Substrates (Glucose, Fructose & Starch) Clamp Stand Diagram: Hypothesis: In my investigation I will change the different substrates & measure the amount of Carbon Dioxide gas collected. Using a monosaccharide (Glucose), a disaccharide (Fructose), and a polysaccharide (Starch) as the substrates. I think that the glucose will produce the most Carbon Dioxide gas, as it is a monosaccharide, and will be easier to break down as it has fewer bonds to break. ...read more.

Middle

(ml) Start End Total Start End Total Monosaccharide 0.0 0.0 0.0 0.5 2.5 2.0 1.0 Disaccharide 0.0 0.5 0.5 2.5 3.0 0.5 0.5 Polysaccharide 0.5 0.5 0.0 3.0 5.5 2.5 1.3 Observations: Glucose produced the most amount of froth, and starch the least. Graph: See over page. Conclusion: I have found the effect of different substrates on fermentation by yeast. From my results I can see that the polysaccharide produced the most carbon dioxide, and the disaccharide the least amount. The polysaccharide (Starch) produced 1.3ml of Carbon Dioxide, and the disaccharide (Fructose) only 0.5ml. This is clearly shown on my graph. Evaluation: The results that I have gained are not reliable. This is because the first set of results taken was clearly wrong. I thought that there might have been an air leak in the bung or delivery tube, so I changed them for the second set of results, which appeared to work better. ...read more.

Conclusion

There may have been a leak in the delivery tube or bung, as I discovered in my first attempt, and so the results would be inaccurate. If the measuring cylinder were tilted when I read off my results then I would have inaccurate data. Because of these inaccuracies, I believe that all of my results are anomalies. If I were to improve on this experiment, and do it again I would change a few things. I would try to prevent air escaping by putting Vaseline around the rim of the bung, I would repeat all of my results at least 3 times to make them accurate and reliable. I would try to ensure I did not heat the water higher then 40�C so not to denature the enzymes, I would shake the contents to make sure all the substrate was dissolved, and I would make sure there was enough of both enzyme and substrate. This would make my results a lot more accurate and reliable. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Green Plants as Organisms section.

Found what you're looking for?

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

Here's what a teacher thought of this essay

4 star(s)

This is a good write up but it lacks a little bit of depth in places. It shows a little confusion on the molecules used that could easily be sorted out by including some diagrams.

It could be enhanced by trying to expand a little on some of the failings in the results. The writer could try and explain why they got some of the results rather than simply stating it. Some more technical vocabulary would also help.

****

Marked by teacher Sam Morran 15/05/2013

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 GCSE Green Plants as Organisms essays

  1. Peer reviewed

    An Investigation into the Effects that Different Light Intensities have on the Speed of ...

    5 star(s)

    I have also taken into consideration the fact that the light might get quite hot. However, fortunately a projector light doesn't seem to get very hot so this should not be a problem Culturing the Woodlice: It will be necessary to keep the woodlice for a few days and so

  2. Factor affecting the rate of fermentation.

    * No eating or drinking in the lab * Don't run around or play in the lab, you might have an accident. * Be careful when using NaHCO3 * Always wear a lab coat to provide protection for clothing. * When something get into eyes, flush it out by water immediately.

  1. Determine the water potential of potato tuber cell with the varying affect of solute ...

    Its surprising because I used my own scientific knowledge plus my preliminary work which I knew was not very accurate. Next was the prediction fro the 0.8 mol dm-3 sucrose solution. I predicted that there will be a larger loss of water therefore loss of mass for this solution.

  2. Investigating the Factors Affecting Respiration in Yeast.

    From this I will be able to calculate how long each experiment will take as I need to decide how long each experiment will last after the water is equilibrated. The time we need to wait for all the air to be pressured out of the syringe is 5 minutes

  1. Investigating the effect of concentration of sugar on the respiration rate of yeast

    After heating the yeast to the right temperature we leave the test tube with the yeast in the water bath so the temperature stays constant through the test. � We then measure the amount of sugar needed and we prepare a beaker with water.

  2. What is the effect on the rate of respiration of yeast cells with glucose ...

    100ml beakers Containing mixtures of dry yeast and glucose which will be dissolved in water. They can be handled with ease and minimum difficulty. It is large enough in size to hold the required amount of solution. 250ml beakers To hold large volumes of water.

  1. What effect does the sucrose concentration have on osmosis?

    Also, I must make the surface area available the same. Each of the potato chips will be cut 3cm by 1cm by 1cm. 2. After weighing the potato chips I will place them into 5 different test tubes. Now I must make the solutions of distilled water and sucrose concentration.

  2. How Temperature Effects the Movement of Pigment Through Cell Membranes

    distilled water the beetroot cylinders are placed into to be heated each time, also the time in which the beetroots are washed to begin with will be the same. The heated distilled water that the beetroot cylinders are put into will only be in the water for one minute otherwise

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