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

Biology Investigation : Yeast-Alginate

Extracts from this document...


´╗┐Biology Investigation : Yeast-Alginate Plan: I plan to investigate the rate at which the enzyme catalase (found in yeast) breaks down hydrogen peroxide into water and oxygen. There are many factors I could vary in this experiment but I have chosen to vary the concentration of the hydrogen peroxide. I will make beads of yeast alginate by mixing 5cm3 of yeast (which contains catalase) and 5cm3 of alginate and stir thoughly with a glass rod. I will allow drops of yeast alginate to fall off the end of the glass rod into a small beaker of calcium chloride. I will make 50 beads and pick out 24 which are 5mm in diameter with forceps (I will measure them using graph paper). I will then drop a yeast bead into the substrate (hydrogen peroxide) where it will react. The yeast alginate bead will fall through the hydrogen peroxide (20cm3) to the bottom of the test tube. When the bead gets to the bottom of the test tube the catalase in it will start to breakdown the hydrogen peroxide into water and oxygen. As it does this oxygen bubbles start to from on the surface of the bead as it is a product of the breakdown of hydrogen peroxide. ...read more.


I predict that if the concentration of the hydrogen peroxide is too small the bead will not rise to the surface. I predict this because in a low concentration there are a very small number of reacting particles in the solution and not enough to breakdown into oxygen to carry the yeast alginate bead to the surface. This diagram would result in one successful collision. But the diagram underneath in which the concentration of the hydrogen peroxide is doubled two successful collisions will occur. This diagram helps me explain my prediction. The substrate (hydrogen peroxide) and the catalase molecules are continuously on the move. Every so often they will collide so that the substrate molecule(s) fits into the enzyme?s active site. Enzymes work best when they have a high enough substrate concentration for the reaction they catalyse. If too little substrate is available the rate of the reaction is slowed and cannot increase any further. Obtaining evidence Volume of hydrogen peroxide (cm3) Volume of water (cm3) % hydrogen peroxide Time taken (secs) 1st experiment Time taken (secs) 2nd experiment 20 0 100 11.13 10.39 17.5 2.5 87.5 12.01 12.16 15 5 75 12.74 12.74 12.5 7.5 62.5 12.89 13.34 10 10 50 14.69 14.95 7.5 12.5 37.5 14.96 15.66 5 15 25 19.11 20.53 2.5 17.5 12.5 30.98 36.72 Volume of hydrogen peroxide (cm3) ...read more.


Another anomalous result is when the hydrogen peroxide was at 87.5% concentration. The yeast alginate bead took more time to rise to the surface of the hydrogen peroxide than would be expected by looking at the line of best fit. There are many reasons why this could be. I may have dropped the bead in lower than the other beads so it took longer to reach the bottom of the test tube because it had less potential energy. Another reason might be that the bead I picked for that particular experiment might have been smaller than the rest so had less of the enzyme catalase in it so took longer to breakdown the hydrogen peroxide. If I were to do the experiment again I would definitely repeat the results more times to minimise the effect errors have on the average and use more concentrations of hydrogen peroxide to make the results more accurate and reliable. Further work I could do to provide additional evidence for my conclusion would be to investigate different catalysts / enzymes e.g manganese (IV) oxide and compare the results and the graphs to the results and graphs I got by using yeast alginate beads as a catalyst. I could also use different forms of catalase e.g liver. I could find out if the curves of the graphs are the same or these sort of results just happened for this catalyst / form of catalyst. ...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. The effect of Copper Sulphate concentration on Catalase activity on Hydrogen Peroxide.

    using my data related to the experiment at 0.75 moles, at 30 and 120 seconds. I displayed the data that I 1.00 M Experiments Average Standard Deviation Coefficient of variation 1 2 3 Time (sec) Volume (ml) Volume (ml) Volume (ml)

  2. A Level Biology revision notes

    gradient o When pressure is equal on both sites net flow ceases (equilibrium) o The pressure is said to be hydrostatic (water-stopping) Water Potential * Measurement of ability or tendency of water molecules to move * Water potential of distilled water is 0, other solutions have a negative water potential * Hypotonic: solution with a lower conc.

  1. To investigate the rate at which hydrogen peroxide is broken down by the enzyme ...

    Finally I think had smaller quantities of hydrogen peroxide solution and celery solution been used a greater range of values could have been tested giving a more extensive graph. Overall I think that the experiment was completed to the best of its potential, and that the results were sound, and

  2. Catalyse Investigation

    This means that the results of the experiment are presented in a clear and orderly fashion that allows patterns in the results to become more obvious. The rate of reaction was calculated by dividing 1000 by the time taken for the quantity of gas to be produced from the reaction.

  1. Investigate how concentration of the enzyme catalase in celery tissue alters the rate of ...

    the concentrations used, the times when results were noted down, the use of a holed rubber bung with delivery tube and how solutions were prepared. The concentrations used in the Agreed Experiment ranged from 0% to 100%, with a factor of 25%, whilst my experiment was to utilise concentrations with the factor of 20%.

  2. Reaction of Catalase and Hydrogen Peroxide

    the higher the temperature the greater the kinetic energy of the system. Increase in the kinetic energy of a system results from increase in the kinetic energy of the system. This has several effects on the rates of reaction. More energetic collisions.

  1. An investigation to see how different concentrations of aspirin affects hydrogen peroxide breakdown by ...

    Non-competitive inhibitors work by deforming the shape of the active site, or the whole enzyme, which nevertheless deforms the active site. Competitive inhibitors are molecules which have a similar structure to that of the substrate. If the competitive inhibitor meets an enzyme, it may temporarily block the active site.

  2. Investigating the break down of Hydrogen Peroxide using catalyst

    their active site becomes permanently distorted which means that the lock and key reaction with the substrate no longer works. Below a certain temperature the enzymes will not function properly because they do not have enough kinetic energy to collide successfully with the substrates.

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