required practical 1

Question 1

what are the factors that affect enzyme activity?

Answer 1

temperature
pH
substrate concentration
enzyme concentration

Question 2

equation for rate of reaction

Answer 2

change in reactant or product/time

Question 3

how is a control set up?

Answer 3

replace enzyme solution with distilled water or boiled enzyme solution

Question 4

method

Answer 4

1. 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
2. take 3 test tubes and measure 3cm3 of milk in each, place in a water bath at 10c for 5 minutes
3. add 5cm3 trypsin to each tube simultaneously and start timer
4. record how long it takes milk samples to completely hydrolyse and become colourless
5. repeat these steps using different temperatures
6. find the mean time for milk to be hydrolysed

Question 5

what is the effect of temperature on enzyme activity?

Answer 5

• 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

Question 6

limitations of method

Answer 6

• 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