required practical 1 Flashcards
rate of an enzyme controlled reaction
1
Q
what are the factors that affect enzyme activity?
A
temperature
pH
substrate concentration
enzyme concentration
2
Q
equation for rate of reaction
A
change in reactant or product/time
3
Q
how is a control set up?
A
replace enzyme solution with distilled water or boiled enzyme solution
4
Q
method
A
- make two control samples
- take two flat bottomed tubes
- add 5cm3 of milk suspension to each tube
- add 5cm3 of distilled water to one tube and 5cm3
of hydrochloric acid to the other - take 3 test tubes and measure 3cm3 of milk in each, place in a water bath at 10c for 5 minutes
- add 5cm3 trypsin to each tube simultaneously and start timer
- record how long it takes milk samples to completely hydrolyse and become colourless
- repeat these steps using different temperatures
- find the mean time for milk to be hydrolysed
5
Q
what is the effect of temperature on enzyme activity?
A
- as temp increases, kinetic energy increases so more ES complexes form. ROR increases to optimum temperature
- beyond optimum, bonds in tertiatry structure break so no ES complexes form and ROR decreases
6
Q
limitations of method
A
- solution going colourless is very subjective
- water bath is not thermostatically controlled
- not enough intermediate pH values taken
- range of tested pH not wide enough