Method and Materials
To carry out this experiment we used:
- Funnels (same Width)
- Beakers
- Pepsin
- pH Buffer
- Stopclock
- Gelatine
Instructions
- Place a funnel securely using a clamp stand, overhead a beaker
- Add 10cm3 of Pepsin to 7 Test Tubes
- Add 3 cm3 of pH buffer to each of the above 7 test tubes
- Mix well, and pour into the gelatine trays and mix the gelatine, using a string rod, for 15 seconds
- Pour the gelatine down the funnel and start the stopwatch and record the time taken for all the gelatine to pour into the beaker
- Repeat the experiment with different concentrations of pepsin i.e. 9cm3 Pepsin and 1cm3 Water, 8 cm3 Pepsin and 2cm3 water etc.
Results
Conclusion
By analysing my results I can see that as the concentration of enzyme decreased the gelatine took longer to pass through the funnel. My results also support my prediction that I as the concentration of enzyme increase the more enzyme activity will take place i.e. in this case the increase of protease enzyme will make the gelatine more runnier (break it down easier/quicker).
My results correspond to the biology behind this experiment as more enzymes, higher concentration, contain more active sites thus more substrate binding complexes can be made. This allows more substrate to be broken down into amino acids, in or case breaking down the gelatine and making it runnier.
Evaluation
To make this experiment fair we used the same amount of gelatine for each set of results and the same amount of pH buffer. If more gelatine was used it would take longer to breakdown and vice versa if there was less gelatine.
pH buffer was used to ensure that the enzyme was not effected by any other pH levels thus to eliminated any problems for the enzymes. pH levels can affect the ionic bonds between amino acids in protein molecules which makes the dysfunctional.
Stirring the gelatine could have also affected our results, but to ensure it was accurate as possible, we timed the how long we stirred for, and tried to keep a standard stirring motion for each gelatine tub. To minimise this error a machine may be used instead of hands to ensure even stirring and equal stirring for all the gelatine tubs.
The dependent variable is the rate at which the gelatine passed through the funnel. Any of the above could have affected this rate and made the experiment void.
To avoid contact with the pepsin, we used gloves whilst handling and wore goggles to avoid any splashes towards the eyes.
