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

An investigation to see whether the concentration of Sucrose effects the amount of Carbon Dioxide released from the respiration in yeast cells

Extracts from this document...

Introduction

An investigation to see whether the concentration of Sucrose effects the amount of Carbon Dioxide released from the respiration in yeast cells Aim: The aim of this investigation is to discover whether the volume of carbon dioxide released from the respiration of yeast is effected by the concentration of sucrose solution that the yeast uses up as a raw material in it's respiration. Prediction: I predict that as we increase the concentration of the sucrose solution, the quicker the reaction will occur. Also, the greater the concentration the more carbon dioxide will be released, because there will be more sugar in the solution with the greater % and so more raw material which is the limiting factor, this would result in more respiration occurring. I could also predict that if the concentration of the sucrose solution is doubled, the amount of carbon dioxide produced by the larger concentration would be twice as much as the smaller concentration has produced within a given time limit. Hypothesis: When yeast is added to a sugar solution (in this case sucrose) a reaction occurs. This reaction is called fermentation and is widely used throughout industry. Yeast is a living cell and so it respires. This is why the reaction occurs because the yeast is using the simple sugar in the solution to respire on. The process however, is anaerobic respiration because oxygen isn't a raw material in the reaction. Yeast Glucose Alcohol + carbon dioxide (Ethanol) As can be seen above in the word equation the products of the fermentation are ethanol and carbon dioxide. ...read more.

Middle

From observing the graph it is clear to see that all the lines descend this represents a loss in mass. This mass loss should equal the mass of carbon dioxide released from the experiment because the other product is a liquid and so remains in the container and hence will be accounted for when the experiment is massed. The results can also show that as the concentration rises the overall total mass loss increases; this is the case for the 1%, 5%, 10% and 15% sucrose solutions. The mass lost in the experiment using 20% sucrose solution seems to be the same if not less than the mass lost in the experiment using 15% solution. I have drawn on the graph to identify the overall mass loss more easily. The table below shows accurately the exact overall loss in mass. As I said in my analysis of the graph I thought that the biggest overall mass loss might be noticed in the experiment using 15% sucrose solution. Up until the experiment using the 15% solution the overall mass lost rose as can be seen on both the table below and the graph. This suggests that the optimum % sucrose solution for yeast (at the quantity of yeast we used) to respire on is 15. concetration (%) 1 5 10 15 20 complete mass loss (g) 2.6 6.81 12.16 15.2 14.22 For the % solutions lower than 15% it is clear that there was a lower quantity of sugar that the yeast had the potential to respire on. This is because as we can observe if we increased the amount of sugar in the same volume (increased the % of the solution) ...read more.

Conclusion

So it was a suitable procedure that was carried out. I think that the investigation was very reliable and that the results are gathered and interpreted were enough to base my conclusion upon. Maybe to improve the experiment we could put the five separate experiments into the same water bath ensuring that they are all at the same temperature. However in doing this I'm sure the results would be very similar if not exactly the same. As I said earlier I could extend the investigation by investigating the total mass loss when % concentration solutions above 20% are used; to see whether the overall mass loss increases, decreases, or stays the same when the concentration is above the optimum concentration. I would probably predict that the rate of respiration and amount of respiration occurring would be less than in the 15% sucrose solution because I have found out that as the concentration rises above the optimum concentration the rate of reproduction of the yeast cells decreases, so there will be less respiration occurring as there is less yeast cells. I could keep the same concentration and the same amount of yeast and the variable in this investigation could be the pH or the temperature. I would expect a pattern to emerge with the temperature as enzymes that would breakdown the sugar in the solution would denature and so respiration wouldn't be able to occur because glucose won't be present. The pH would also effect the results as different enzymes have different optimum pH's. Also different amounts of a catalyst could be added, however this would be very difficult. Other possibilities could include the variables being different concentration/quantities of yeast, or different types of sugar solutions at the same concentration. Tom Warren Biology coursework Mr Robinson ...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 Exchange, Transport & Reproduction 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 Exchange, Transport & Reproduction essays

  1. Peer reviewed

    The comparison of antibacterial properties of herbal products and standard antibiotics

    5 star(s)

    It was difficult to specifically ensure 2.0ml of bacteria was placed onto each plate, so at this point accuracy was a problem but not immensely as no major reading was affected. The yield of accuracy became a problem yet again with the concentrations, although for the main the herbal discs were dried before, the concentration of them was still unaware.

  2. Peer reviewed

    Effect of Caffeine on the Heart Rate of Daphnia

    3 star(s)

    It is by tapping a pencil on a piece of paper and count up the pencil marks at the end of the time period. Clearly, this method is more primitive and errors are more likely to occur because some pencil marks may be too close together and cause confusion in counting the number pencil mark.

  1. Rate of Respiration

    This is important to respiration and my investigation because the substrates that I will be using are polar. Hence, before the yeast can start respiring the yeast first must saprophytic digest the substrate, and then absorb the products via facilitated diffusion, as the sugars are polar and cannot diffuse via lipid diffusion due to the phospholipids bi-layer.

  2. The Effect of Different Substrates on the Rate of Respiration on Yeast (Saccharomyces cerevisiae).

    Sucrose is hydrolysed` (inverted) into glucose and fructose by invertase present on the cell surface of regular bakers' yeast. Lactose (milk sugar) is not fermented by regular bakers' yeast. This is the only variable that is being manipulated Conclusions and Predictions Having studied the theory on yeast, the substrates, and

  1. To find out the factors affecting the refractive index of liquid by using different ...

    - Distance between the normal line of refraction and the initial mark (L2) - Depth of the solution in the container (d) - The temperature of solution (t) - The value of refractive index (�), which have to be calculated by the formula: Where h, x, L2 and d are

  2. The effect of different sucrose concentrations on the growth of yeast.

    five different concentrations of sucrose solution, methylene blue, a capillarity pipette, yeast and thirty test tubes. My hypothesis is that the yeast growth will increase with the increased sucrose concentration. My null hypothesis is that there will be no difference in the yeast growth in each of the sucrose solutions and if there is it is only by chance.

  1. Investigate one factor that affects the rate of respiration of yeast

    then leave the active site, which is now ready to do the same to another glucose molecule. So if there are many glucose molecules (10% concentration) there will be more chance that these molecules can enter the active site and produce a fast rate of fermentation. The predicted outcome (graph)

  2. Design an experiment to investigate the effect of temperature on the movement of a ...

    shorter amount of time then less of the pigment will be in the water. Also I have been researching the half-life of beetroot (source- www.biologymad.com). The half-life of beetroot pigment is 413 minutes at 250C, but only 83.5 minutes at 600C.

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