• 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 effect of temperature on the rate of respiration in yeast

Extracts from this document...


An investigation into the effect of temperature on the rate of respiration in yeast There are two types of respiration in yeast: Aerobic: Anaerobic: Glucose Carbon dioxide + ethanol + energy Respiration is controlled by enzymes, which are proteins which speed up one or more biological reactions. Within any cell many chemical reactions are going on at any one time. Yeast has many different types of enzymes that speed up respiration. Prediction I predict that as temperature increases, the rate will also increase, until a certain optimum temperature, after which, the rate will decrease until the rate is zero as respiration has stopped completely. REASON As temperature increases, rate of respiration increases, because particles move faster and with more energy, which in turn means more particles collide with enough energy to react. However, as temperature increases, enzyme stability decreases, so at temperatures above the optimum temperature, the rate will decrease, until all the enzymes have been fully denatured and all the active sites have been lost. Enzymes speed up reactions in organisms. Each enzyme works on a specific substance, called its substrate. The diagram below shows an "E" (an enzyme) catalysing the breakdown of "S" (the substrate) into two different products ("P"). Catalysis occurs because substance S fits precisely into surface of the enzyme E, so this reaction and no others are speeded up. ...read more.


* Different volumes of water in the water bath will affect how much it changes the temperature of the yeast and glucose mixture. Preliminary experiment: I wanted to see if I needed to make any changes to my experiment, so I carried out the experiment as planned so far, and I got the following results: Temperature (oC) CO2 collected (cm) (Run1) CO2 collected (cm) (Run 2) 20 oC 0 0 31 oC 5 5 41oC 7 6 48 oC 6 7 59 oC 6 5 73 oC 0 0 I did two runs, so I could see anomalies if I got any. During this experiment I noticed that the contents of the test tube where bubbling over into the delivery tube. Another problem was that I could not see the colour of the diazine green in the mixture so it was hard to tell when aerobic respiration had fully stopped. Also as the mixture bubbled over the paraffin had no effect. These are probably the reasons that my results don't show a good trend. This means I am going to have to modify my experiment: Modified Method I will carry out my experiment as I planned before, but I will use 6 drops of diazine green instead of 2, because with 2 drops I couldn't see the colour so I couldn't tell when aerobic respiration had stopped, but should definitely be able to with six. ...read more.


If I wanted I could also find a more accurate optimum temperature by using a small range of results at small intervals, for example if the highest reading was at 47 oC, I could then measure the rates of respiration at the following temperatures: 46.5, 46.6, 46.7, 46.8, 46.9, 47.0, 47.1, 47.2, 47.3, 47.4, 47.5 (oC) This would give me a more accurate optimum temperature, as the optimum temperature is only as accurate as the temperature intervals are small. Another experiment I could do would be to find the temperature at which all the enzymes in yeast involved in anaerobic respiration are fully denatured. I would repeat the experiment with the same changes (conical flask, gas syringe and thermostatically controlled water bath) but used the following temperatures instead: 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76 (oC) Then I could find this a more accurate value, for example if 70 oC was the lowest temperature which gave all the volumes of carbon dioxide produced in 3 minutes (cm) as 0, then I would do the same but with the temperatures: 74.1, 74.2, 74.3, 74.4, 74.5, 74.6, 74.7, 74.8, 74.9, 75.0 (oC), and then the lowest of these values which gave which gave average volume of carbon dioxide produced in 3 minutes as 0 would be the temperature at which all the enzymes in yeast fully denature (to 1 decimal place). ...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 Humans 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 well written report that shows good understanding of the process of an investigation.
1. There are several subheadings missing that would improve the structure of the report.
2. Researched information needs to be directly referenced.
3. The conclusion explains the pattern well but should use data from the investigation to back it up.
4. The evaluation is the strongest section and includes a good amount of detail.

Marked by teacher Luke Smithen 16/07/2013

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 Humans as Organisms essays

  1. Marked by a teacher

    Biology Revision notes - Human Biology

    5 star(s)

    it in her breast milk due to famine and lack of protein for her body. Children with Kwashiorkor are short and underweight. They may look fat as they have swollen abdomens due to fluid accumulation. They are weak as their muscles are under developed.

  2. Marked by a teacher

    Design an Experiment to show how exercise can affect Heart Rate in Humans.

    4 star(s)

    Using an electronic heart monitor would evade any possibility of human error or limitation. By also looking at the table of results, a considerable deviation in heart rate between the replicates of different people is noticed and this would decrease the reliability of the experiment.

  1. Marked by a teacher

    The effect of different sugar substrates on the rate of yeast respiration

    4 star(s)

    In yeast the end products of Glycolysis is carbon dioxide and pyruvic acid which is then converted into ethanol. Although yeast can survive during anaerobic respiration, it does not grow and multiply as it would during aerobic respiration. Anaerobic respiration releases much less energy than aerobic respiration.

  2. An experiment to investigate the rate of anaerobic respiration of yeast in various respiratory ...

    Yeast is a fungus. Fungi are either unicellular or filamentous. All yeasts are unicellular and reproduce by budding and the parent cell buds off a daughter cell and this process is repeated indefinitely. Yeast feeds by heterotrophic nutrition because they lack chlorophyll and therefore are non-photosynthetic.

  1. Human biology short notes

    fat molecules * Passed into the lacteal * Utilized for cell formation, energy * Excess is stored as insulation Diet * Balanced Diet is a diet which contains all nutrients required by the body in correct portions * A balanced diet contains :- Carbohydrates, Fats, Proteins, Minerals, Vitamins, Water, Fibre

  2. To investigate how the heart rate and breathing rate increase with exercise.Scientific KnowledgeAerobic respiration ...

    This system involves negative feedback. Feedback happens when a change in a system can somehow act to affect whatever it was that caused the change. Negative feedback helps to keep things the same. In this case the carbon dioxide rise causes an increase in breathing rate which leads to the carbon dioxide level being reduced and eventually corrected.

  1. The effect of temperature on insect respiration rates

    Particle theory dictates that increasing the temperature provides kinetic energy to all molecules so causing them to move more quickly so react more often, so enzyme activity increases and the Q10 law states that increasing the temperature by 10�C should double enzyme activity.

  2. Experiment to Investigate Factors Affecting the Rate of Respiration in Yeast

    I then put 1 gram of yeast into a test tube with 10cm? of 12% glucose solution inside. This showed us that in the temperature 60?C, the yeast could still respire, but quite slowly compared with another experiment I set up at 40?.

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