Bromothymol blue is a pH indicator. It is blue in alkaline solutions and turns yellow as the pH decreases below 6.0.
It can be used to investigate the rate of lipid digestion by the enzyme lipase.
Samples of single cream mixed with sodium carbonate (an alkali) and bromothymol blue were incubated with lipase at different temperatures.
The time taken for the mixture to change from blue to yellow was recorded and used to calculate the rate of reaction.
Explain why the mixture turns from blue to yellow when lipase breaks down the lipids in the cream.
