Hydrogen Peroxide and Catalase

... e not done on the same day as each other, all the better to prevent factors like which potatoes I was using and draught in the lab from affecting my average results.

For one of the reactions, take readings of the amount of gas in the burette every 30 seconds. This is to show the activity decrease curve throughout the individual reactions.

This is a summary of the steps that and I will take to reduce the amounts of errors affecting the results.

· · Keep the level of water in the ice cream tub the same and the retort stand with all the clamps and the funnel on it to make sure that the oxygen has the same distance to travel underwater each time.

· · Use a burette (reasons already explained in plan).

· · Use a compromise between factors (e.g. large volumes/longer times) to reduce percentage inaccuracies where possible.

· · Record the temperature of the hydrogen peroxide, so that I can use the Q10 formula to temperature balance the results.

· · Repeat each experiment 3 times to get an average.

· · Keep the time that I collect for (five minutes) and amount which I collect (20 ml) there same so that the reactions are at the same stage in their natural exponential decay curve when the measurements are taken.

· · Use potatoes from the same batch for all of the reactions.

This is what I will do with my results and how I will record and process them.

· · This is the table in which I will record my observations.

Experiment

Substrate the ones (%)

*Oxygen produced in 5 min(ml)

#Time taken(20 ml)(s)

Temperature of solution/degrees C

Rate 1(from*)

Q10 balanced rate 1

Rate 2(from#)

Q10 balanced rate 2

Substrate concentration,S

1

0.0%

13

0

0

0

0

(moles per litre)

2

0.0%

15

0

0

0

0

0

3

0.0%

We

0

0

0

0

0

Average

0.0%

14

0

0

0

0

0

1

2

5.0%

5.0%

17.5

0.021

0.024

0.01345895

0.015381657

1.47

I will then:

· · Plot a graph of rate against (average) substrate concentration and compare it with the prediction.

· · Calculate the amount of enzyme present and compare this with the prediction.

· · Calculate the Michaelis constant (KM) for catalase.

· · Decide whether the Q10 Formula is accurate for catalase.

· · Plot a graph of rate against concentration with all the repeats and the averages on and determine from the line of best fit which results were anomalous.

· · Decide what factor might have caused the anomalies

There are many variables that affect the results and a fluctuation of any of those that I am controlling will result in incorrect, biased or anomalous results.

The factors that are most likely to cause inaccuracies are:

· · The accuracy to which I can dilute the hydrogen peroxide, including; drips, pipettes leaving different amounts in the tip, parallax error (minimal), gradual breakdown of the hydrogen peroxide and impurities in the beaker including water (after being washed out).

· · The accuracy to which I can control the surface area o ...