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

The effect of concentration on catalase enzyme

Extracts from this document...


Prediction ? I predict that there will be a higher concentration of catalase in the animal tissue than in the plant tissue so the discs soaked in animal tissue extract will take less time to rise. This is because the tissue will contain an appropriate amount of enzyme to break down any hydrogen peroxide that it makes. As hydrogen peroxide is a toxic product of aerobic respiration, the concentration will be highest in the most rapidly respiring tissue. Muscle respires rapidly because it needs ATP to contract and liver respires rapidly because it carries out many complex biochemical reactions. The potato and celery do not need much ATP, so respiration rate is slower, catalase present will be less, so discs will take longer to float to the surface. Experimental design The independent variable is the type of tissue source and there will be 5 different ones including both plant and animal material. The dependant variable is the time taken (s) for a disc soaked in catalase to rise up through a solution of hydrogen peroxide. This is a measure of the time taken to produce enough oxygen to make the disc buoyant (less dense than water). ...read more.


Care will be taken when handling it and safety spectacles worn throughout. Any spills will be reported to the teacher and then cleared up promptly under supervision. Results Time taken for disc to rise to surface (s) Catalase source Rep 1 Rep 2 Rep 3 mean Potato 21 23 20 21.3 Celery 22 25 20 22.3 Thigh 20 20 19 19.7 breast 40 36 38 38.0 Liver 5 8 9 7.3 Trends The discs soaked in the liver extract rose to the surface in the shortest time with a mean of 7.3 s. The discs soaked in turkey breast took the longest time to rise to the surface with a mean of 38.0 s. Reliability There was overlap between range bars of results from the potato, celery and thigh tissues, hence the differences in mean are not reliable. Accuracy Some discs took longer to rise because they ?rubbed against? the side. Improvements 1. There is no temperature control, although it was monitored. If the tube of hydrogen peroxide were maintained in a 250C thermostatic water bath until just before the discs were added, it would be constant. ...read more.


Further Work In further work it would be interesting to explore how the time taken for discs to rise (dependent variable) changes with pH. The independent variable would be pH, changed using pH 5, pH 6, pH 7, pH 8, pH 9, pH10 buffers. The controlled variables would be: 1. The concentration of tissue extract (enzyme source) would be 25% 2. Volume and concentration of hydrogen peroxide solution (substrate) will be kept the same for each disc (20cm3 of the 2% solution) 3. The time that the discs were left in tissue extract was kept constant at 30seconds using a stopwatch. 4. Temperature ? the whole experiment will be carried out at 20oC in a thermostatically controlled water bath. 5. 5cm3 of each pH buffer solution will be used. Most body cells work best in a pH close to neutral, hence the time taken for discs to rise will be least at this pH. At a slightly lower or higher pH (6 and 8) the time taken for the disc to rise would be longer as the charges on active site and substrate will repel. At extreme pH the reaction may stop if ionic bonds break and the enzyme denatures. ...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. Investigation of the effect of adding different concentrations of NaCl to an enzyme-substrate (amylase-starch) ...

    This gives a chance to record some sensible results. Next the volume of starch used should remain the same, as if it is also reduced, it will have the counter effect on the reducing of the amylase; therefore in order to increase the time taken to break down starch the volume of starch should remain 2cm�.

  2. The effect of Copper Sulphate concentration on Catalase activity on Hydrogen Peroxide.

    If the observations follow a Gaussian distribution then the interval mean +- SD includes 68% of the observations. Hence in our series for 30 sec The interval that contains 68% of the observation is: 9.5-11.1, while for the 120 sec is 13.4-14.0.

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

    pH: H2O2, Hydrogen Peroxide, could affect the pH level of the solution, but I have limited the consequences by using the same volume, concentration and source of H2O2. The effect of Surface Area is controlled by the liquidising of the celery tissue.


    The enzyme will be working as fast as it possibly can but even still, the no. of substrates present will be too many for the enzymes to cope with. So any further increase will have no affect whatsoever on the rate of the reaction because products will be formed at the constant rate by the enzymes.

  1. This is an experiment to show how different concentration of celery tissue enzyme, catalase ...

    A very small amount of enzyme is needed to catalyse large amount of substrate into products, through their lifetime. The number of substrate molecule turned into products by one molecule of enzyme in a minute is called turn over number.

  2. An Investigation on the Effect of Enzyme Concentration on rate of hydrogen peroxide breakdown.

    This leads to the alteration of the very precise shape of the enzyme and more importantly the active site, the enzyme has been denatured. Therefore, the substrate molecule is not able to fit into the active site and enzyme activity is dramatically lowered.

  1. Investigating the break down of Hydrogen Peroxide using celery tissue to supply the enzyme ...

    Not all collisions, however, bring about chemical change. A collision will be effective in producing chemical change only if the atoms or molecules brought together possess a certain minimum value of internal energy, equal to the activation energy of the reaction.

  2. Investigating How the Concentration of the Enzyme Catalase in Celery Tissue Alters the Rate ...

    The R group of an amino acid may be simply a hydrogen atom, in the most basic amino acid glycine, or could be seven molecules long in arginine. However these R groups are hydrophilic and therefore allow the enzymes to be dissolved in water, important for our experiment.

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