investigating decay

• to investigate decay, use milk and lipase
• to detect when the milk have decayed, use phenophthalein solution
• when the milk has decayed, the phenophthalein solution will turn pink, as the lipids in the milk will have turned into glycerin and fatty acids
• to make sure the solution in the milk is originally alkaline, add 7 cm cubed of sodium carbonate
• rate = 1000 / time
• adding bile will increase the speed of decay as it emulsifies the lipids, giving them a bigger surface area for the enzyme to work on