• 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. Marked by a teacher

    Investigate the effect of huddling on heat loss.

    5 star(s)

    The water temperature is wanted, because we are measuring the heat loss from the water, which would be the 'body' of the organism. The 'test tube' perhaps can be seen as the skin or fur of the organism. Also, glass retains heat.

  2. Peer reviewed

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

    5 star(s)

    they need to be looked after correctly and handled in the right way. Most importantly, humidity needs to be maintained. Therefore, a couple of potatoes with holes in them will be placed in the bottom of the culture container as these retain moisture and provide ideal places for the woodlice to live in temporarily.

  1. Investigating the Factors Affecting Respiration in Yeast.

    Diagram of the apparatus Clamp Thermometer Syringe with yeast, glucose and air Water Bath Example of Result Table (One table for each Temperature) Test Period Of Time** Intended temperature Actual temp. at beginning Actual temp. at end Average temp.* No.

  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. An Investigation into Water Loss from Plants.

    All leaves must be approximately the same size and all from the same bush to ensure continuity. * 20 test tubes: To place the shoots in and hold them in water to ensure they have a continuous supply of water.

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

    % Sucrose % Water Volume (cm3) Initial Mass (g) Final Mass (g) Change in Mass (g) Average Change in Mass(g) % Difference Average % Difference 1 75.00% 25.00% 20 1.90 1.13 -0.77 -40.00% 2 75.00% 25.00% 20 1.92 1.11 -0.81 -42.00% 3 75.00% 25.00% 20 1.93 1.14 -0.79 -0.79 -40.00% -41.00% Exp.

  1. Investigating Heat Loss in Model Animals

    measured using a thermometer every five minutes and the results noted, each time going through the test tubes in the same order. The process is continued until each test tube reaches a steady temperature (room temperature). There were various problems with this method which prompted me to make changes for the full experiment.

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

    � Once we add the sugar into the yeast we place a bung to close the test tube with the solution and attach a tube from the bung to the water filled beaker.

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