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

Yeast Coursework

Extracts from this document...

Introduction

Biology Coursework: Respiration in Yeast Planning Aim The goal of this experiment is to discover how varying the temperature, of a solution of yeast and sucrose, will affect the amount of carbon dioxide produced during a set time period. After I have completed this experiment and obtained enough data, I will analyse and discuss it, and then I will evaluate it. For this experiment, my independent variable will be the temperature, which I will change by adding warm water to it. My dependent variable will be the amount of carbon dioxide given off. My controlled variable will be the amount of sucrose and yeast there is in the solution, and also the time the experiment will be running for, as these are the only factors that can be varied to produce different amounts of CO2. Background Knowledge This experiment involves enzymes, which are biological catalysts. All the chemical reactions in a living organism are collectively known as the metabolism. Anabolic reactions normally need an input of energy, to build up large molecules from smaller ones. Catabolic reactions often release energy when breaking down large molecules into smaller ones. An example of anabolism is the condensation of glucose molecules, which happens in liver cells and skeletal muscle. ...read more.

Middle

During this period, I will prepare for the next temperature, and prepare the yeast and sucrose as above. When the first test is over I will increase the temperature by adding some warm water to the cup from the kettle, to get it to he right temperature. In order to keep the temperature the same throughout the experiment, I will pour some of the hot water into a separate cup, so that I can pour some into the cup if the temperature should fall below a certain point. This should help to keep it a fair test. Safety is always a priority, and it is no different in this case. In this experiment there are no hazards to be wary about, other than the water from the kettle. To stay safe while pouring it, I will place the cup on the desk, and pour the water in slowly. I will also keep my bag out of the classroom, and the chairs under the desks. Prediction I predict that as the temperature is raised, then so will the rate of respiration. I believe that this will continue to happen up to an optimum temperature, at which the active sites of the enzymes will begin to denature. ...read more.

Conclusion

The quality of my evidence is, overall, accurate and also reliable. This is because they follow scientific theory like the 'lock and key hypothesis' and the Collision Theory. It followed my prediction that was based on scientific theory. The results follow the expected pattern, which has reaches optimum temperature and then, when it starts to denature, the respiration rate falls. There was one set of anomalous results obtained in this experiment. This was when the temperature was at 30ºC. I believe these results to be anomalous as the do not follow scientific theory. At this temperature, the rate of respiration does not increase from the first set of results, which were at 20ºC. According to the lock and key hypothesis, a rise in temperature should increase the rate of respiration. This is not the case with this set of results. The rest of the results do, however, follow theory. On the next page there is a table commenting on how the experiment could be improved in order to gain more accurate results, and minimise the risk of anomalies. Possible sources of error/inaccuracy Ways to improve The collecting cylinder. Use one with smaller measurements. Solution not the right temperature. Leave time for the yeast to heat up before adding the sucrose and starting the experiment. The data I've collected is sufficient to draw the conclusion that my prediction was correct. ?? ?? ?? ?? David Hart Biology Coursework: Respiration of yeast -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 Energy, Respiration & the Environment 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 Energy, Respiration & the Environment essays

  1. Marked by a teacher

    effect of temperature on the rate of respiration in yeast

    5 star(s)

    Inactivation by heat denaturation has a profound effect on the enzymes productivity. (Reference 6) Yeast: Yeasts are unicellular fungi. The precise classification is a field that uses the characteristics of the cell. One of the more well known characteristics is the ability to ferment sugars for the production of ethanol.

  2. Marked by a teacher

    Effect of Anaerobic Respiration On Yeast

    5 star(s)

    amounts of yeast could mean varying concentrations of enzymes within the yeast, causing large variations in the rate of reaction Measure out the yeast from the same batch in equalquantities using a measuring cylinder Water in Burette If the water in the burette is not at the same level each

  1. Marked by a teacher

    Fighter Pilot A Statistical Analysis of Reaction time and its Correlation with Dominant ...

    5 star(s)

    Lower Confidence Limits = X - (t x standard error of the mean) t value is taken from critical value tables at a 0.05 probability and N - 1 degrees of freedom Table 8 Calculated data from both samples Subjects Time in seconds (s)

  2. Marked by a teacher

    'An investigation into the ability of two strains of the yeast Saccharomyces cerevisiae to ...

    4 star(s)

    Method Take ten 500cm3 flasks, and using a permanent marker, label five 'baking yeast', and the remaining five, 'wine yeast'. On each of the flasks bearing the mark baking yeast, one of each of the following should be written: control, glucose, maltose, galactose and lactose.

  1. the effect of bile concentration on the activity of the enzyme lipase during the ...

    no longer able to bind to the enzyme, consequently even if the temperature is reduced the damage done to the enzymes shape and active site is irreversible and it will cease to function and be unable to catalyse any reactions.

  2. out how different concentrations of the enzyme pectinase affect the degradation of the substrate ...

    The result of an extreme pH, however, may cause an irreversible change to the enzyme. It may cause the enzyme to change: its protein structure, the binding of the substrate to the enzyme, the properties of amino acids or co-factors involved in the catalytic activity of the enzyme and the ionisation of the substrate.

  1. An investigation into the effects of temperature on the rate of anaerobic respiration of ...

    In general, it has been said that there is a doubling of the rate of reaction for every 10ºC rise this is called the 'Q10=2' theory. This should be observable when the concentrations of the yeast and glucose solution are kept the same.

  2. A Comparative Study of the Density of Patella Vulgata (Common Limpets) in the Optimum ...

    The moon is responsible for creating waves. The gravity from the moon is responsible for the tidal bulges (oceans bulging out at the same time which result in high tides). Due to the earth rotating on its axis, the tidal bulges move back and forth causing high and low tides.

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