Lipase is used in a process that converts lipids into fatty acids and glycerol. A technician compares five buffer solutions before choosing the operating conditions.
Equal batches are allowed to react for 300 s. The temperature and the concentrations and volumes of lipase and lipid are kept the same in every batch.
The table shows the mass of fatty acids produced.
| pH | Mass of fatty acids produced in 300 s in mg\mathrm{mg}mg |
|---|---|
| 4 | 9 |
| 5 | 33 |
| 6 | 54 |
| 7 | 42 |
| 8 | 18 |
For this process:
rate of fatty acid production=mass of fatty acids producedtime\text{rate of fatty acid production} = \dfrac{\text{mass of fatty acids produced}}{\text{time}}rate of fatty acid production=timemass of fatty acids produced
Calculate the percentage decrease in the rate of fatty acid production when the process is run at pH 8 instead of at the pH giving the fastest rate.
Give your answer to 1 decimal place.
The technician tests another batch at pH 9.
Explain how pH 9 could affect the lipase and predict how the mass of fatty acids produced in 300 s would compare with the result at pH 8.
184 exam-style questions on OCR GCSE Biology 1.2 What happens in cells (and what do cells need)?, covering 1.2.1 Structure of DNA, 1.2.2 Nucleotides and complementary bases, 1.2.3 Protein synthesis, 1.2.4 DNA structure and the proteins made, 1.2.5 Investigating enzymatic reactions, and 1.2.6 Mechanism of enzyme action. Each one has a worked solution and a mark scheme showing where the marks go.