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

An investigation into the amount of gas produced by a solution of glucose and yeast.

Extracts from this document...


Biology Coursework: An investigation into the amount of gas produced by a solution of glucose and yeast. Results % Glucose Concentration vol gas (mm3) 0 1 2 4 6 10 0 0 0 0 0 0 0 30 15 10 18 8 15 60 10 13 27 6 10 90 5 12 13 14 10 120 5 15 17 11 12 150 7 20 19 11 16 180 4 18 18 17 15 210 5 22 18 16 18 240 2 15 20 15 16 270 3 15 17 15 12 300 1 15 18 17 5 330 5 5 17 18 5 360 2 5 13 13 5 390 1 5 15 15 9 420 2 3 15 17 2 450 3 5 17 12 9 480 2 2 15 13 12 510 1 3 6 18 12 540 2 3 9 12 9 570 2 4 5 12 9 600 0 1 12 11 8 630 2 4 0 10 6 660 2 2 0 12 9 690 2 3 9 10 13 720 0 2 5 5 11 750 2 3 4 7 6 780 2 1 1 12 3 810 2 3 0 6 9 840 2 1 0 10 6 870 2 3 0 0 4 900 2 2 0 7 ...read more.


Alcohol would also be produced, but the reaction for anaerobic respiration, C6H12O6 --> 2C2H5OH + 2CO2 tells me that for every mole of glucose, two moles of alcohol would be produced, and thus a 1% solution of glucose would produce a 2% solution of alcohol when fermentation is complete, but this is only if the solutions are measured by moles, and in this case, I don't think it is safe to assume that this is so. Therefore, I cannot include this quantitative theory in my explanation. However, I could possibly work out if alcohol was ever a limiting factor by looking at the results; the four percent solution slowed down and basically stopped producing gas towards the end of the experiment. The fact that it stopped producing gas before it had produced double the amount of gas that the two percent solution produced shows that there must have been some limiting factor other than the yeast using up all the glucose. It could not have been that the cells had become plasmolised, because this would have had a much greater effect at the beginning of the experiment when the glucose concentration was higher. Therefore, I suggest that the factor that limited the four percent solution from producing more gas was that the alcohol levels had reached a level high enough to denature the enzymes and kill the yeast cell. ...read more.


Modifications If I were to conduct the experiment again, I would conduct all the experiments myself so that I could make sure that the conditions were exactly the same for every solution, and I would know exactly if something had been a bit odd in a certain experiment. I may also test the alcohol concentration after the experiment has finished so that I could see if that had been the limiting factor. I would also continue the experiment for longer so that I could see which solution ended up producing the most gas. With these bits of information, I would be able to work out the effect of alcohol on the solution, and decide if that had been a limiting factor. If I knew how much longer the solutions had continued to produce gas, then I would be able to test my theory that the six and ten percent solutions would continue to produce gas when all the others had finished. If they had done, then I would know that the limiting factor for those solutions had been the fact that the cells were plasmolised, however, if they had stopped producing gas just after the four percent solution had, then I would know that alcohol had been the limiting factor. Hector Guinness 03/05/2007 1 ...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)

    The third stage of the respiration process is known as the Krebs cycle, which is a closed pathway of enzyme-controlled reactions. The product of the Link reaction (Acetyl-CoA) combines with oxaloacetate, a 4-carbon compound, to form citrate, a 6-carbon compound.

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

    8 Syringes To measure the amount of substrate that I will use. Clam and Stand The test tubes can stand in the water bath. Variables In this experiment I will need to monitor these variables, * Temperature * Volume of glucose concentration * Volume of yeast * Volume of phenolphthalein.

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

    The more phenolphthalein I use the longer it will take the color change to take place. Phenolphthalein Phenolphthalein is an organic compound (C20H14O4) used as an acid-base indicator. The compound is colorless in acidic solution and pinkish in basic solution (with the transition occurring around pH 9).

  2. Affect of sucrose concentration on the rate of respiration.

    An imbalance will upset the results. The amount of yeast will be weighed out on an accurate top-pan balance each time. The temperature is also a important variable which will have to be kept constant as if the temperature is to high the enzymes will be denatured and if is

  1. The aim of this investigation is to find out how concentration of glucose affects ...

    This means there were some fundamental flaws with the experiment that had to be confronted before I could continue. One of the main problems with my preliminary work was that the concentration I used for them was too high for the yeast to function properly.

  2. Investigating the Effect of Glucose Concentration On the Rate of Reproduction of Yeast Cells

    Another difference between the two methods of respiration is the amount of energy released. In aerobic respiration, 32 ATP molecules of energy are released per glucose molecule (see Figure 1). In anaerobic respiration, only two ATP molecules of energy are released for each glucose molecule.

  1. Catalyse Investigation

    It is therefore impossible to include the results which I have classed as anomalous in it the conclusion because I can't work out any explanation for the trend or at indeed find a scientific reason for the type of increase demonstrated.

  2. The factors that affect the respiration of immobilised yeast

    Pyruvate is a compound that contains three carbon atoms and is very important in respiration since it can be converted into either acetate for aerobic respiration or acetaldyhyde for anaerobic respiration.

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