Practical Flashcards
Practical
Make two control samples:
● Take two flat bottomed tubes.
● Add 5cm 3 of milk suspension to each tube.
● Add 5cm 3 of distilled water to one tube- this control will indicate the
absence of enzyme activity .
● Add 5cm 3 of hydrochloric acid to the other- this control indicates the
colour of a completely hydrolysed sample .
2. Take three test tubes and measure 5cm 3 milk into each. Place in water bath at
10°C for 5 minutes to equilibrate.
3. Add 5cm 3 trypsin to each test tube simultaneously and start the timer
immediately.
4. Record how long it takes for the milk samples to completely hydrolyse and
become colourless .
5. 6. Repeat steps 2-3 at temperatures of 20°C, 30°C, 40°C and 50°C .
Find the mean time for the milk to be hydrolysed at each temperature and use
this to work out the rate of reaction
