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

To find out how temperature will affect the amount of carbon dioxide given off from yeast.

Extracts from this document...


Biology Coursework Aim : To find out how temperature will affect the amount of carbon dioxide given off from yeast. Prediction : I predict that the cooler the water we use is, the less bubbles will be produced, if any at all. I think this because the warmer the water the molecules move faster/collide/react and more carbon dioxide will be given off from the yeast due to the enzymes respiring (fermentation). However I know that the enzymes that produce the carbon dioxide via fermentation will certainly denature after exposure to temperatures above that of 40oC. So I believe that anywhere between 20-40oC will produce a good amount of bubbles, less than 20oC will stop the enzymes from being able to produce carbon dioxide because they will simply stop. And above 40oC will more than likely denature the enzymes, resulting in no carbon dioxide bubbles being produced. ...read more.


Apparatus List : For the experiment, I will need : Bung Boiling Tube Clamp Stand Measuring Cylinder Smaller Test Tube Water Third Test Tube Fair Test : To make this a fair test, I will need to keep the same amount of water used in every experiment. The yeast will also be kept the same. I will use the same equipment every time I do an experiment in case yeast is left over in a measuring cylinder. Diagram : Method : 1. Set up all of the equipment as shown in the diagram 2. Measure 25cm3 of water, fill the boiling tube up 3. Measure 20cm3 of yeast, pour it into the smaller test tube 4. Heat the yeast to 20oC 5. Count the number of bubbles formed in the test tube linked to the yeast one. 6. Repeat steps 2-5 using different temperatures (40oC, 60oC, 80oC and 100oC) ...read more.


To avoid this problem I should have heated the water up before adding the dry yeast and sugar. We should have also mixed the yeast every time we took a sample. Maybe the main yeast cells had fallen to the bottom. If we shook the bottle the concentration would be equalled out instead of being at the bottom. Also temperatures above 50oC must have denatured the enzymes therefore we wouldn't have gained any bubbles from the yeast. To gain perfect results I could've averaged my results but unfortunately I got 0 bubbles from all 5 temperatures. I could have changed the water used in the boiling tube to a liquid which is less affected by temperature. I could also use an electric thermometer which would help me greatly as a manual thermometer isn't as accurate as an electric one would be. Finally I could have conducted another experiment to check if concentration of yeast affects the rate of which it respires. I could have kept the temperature at an optimal rate (40oC or so) and tried different concentrations of yeast ...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

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. How temperature affects the rate of photosynthesis.

    and also to obtain a more accurate angle at the end of the shoot. * Improvements to the potometer can be made. For instance a larger measuring tube can be provided which would easily accommodate a relatively large length of oxygen bubble.

  2. Investigation into the Affect of Temperature on Yeast Activity.

    This input variable will vary in each experiment starting at a temperature of 15oC and increase by 10oC until 45oC is reached. I will also include 40oC in the investigation. * The amount of bubbles, which is the outcome variable.

  1. Investigating The Fermentation of Yeast

    The carbon dioxide then builds up and to release the pressure, gets forced out of the end of the rubber tube. I shall then count the bubbles and base the rate of fermentation on the results. I shall count the bubbles over a period of one minute and do this for twenty minutes.


    I will use the same diameter corer and cut all the beetroots to the same length so that the surface area of each beetroot is similar and that the dependant variable is kept the same. I will then using tongs to place the beetroot pieces in a beaker of distilled

  1. Investigating respiration in aged yeast

    I registered the time for each reading using the minute and the second when the particular volume was reached. For each experiment I used the same scale to measure the amount of glucose, so there is no doubt about the quantity used - different scales have different sizes of error,

  2. Construct a rocket from a discarded PET (Polthylene Teraphetlate) drink bottle.

    and the range we got (23.6) is about 23.6-15.93 = 7.66 m<-- we were only 7 meters of the theoretical range. We get a percentage error of about 23.6-15.93/15.93 multiplied by 100 =48 % Method 2. From method 1 we use the time and hence find the theoretical range.

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