A technician investigates lipase, an enzyme that breaks down lipids.
Equal samples of lipase are kept at either 25 ∘C25\ ^\circ\text{C}25 ∘C or 70 ∘C70\ ^\circ\text{C}70 ∘C for 10 minutes. Each sample is then brought to 25 ∘C25\ ^\circ\text{C}25 ∘C and mixed with lipid. All other conditions are kept the same.
| Lipid concentration (g dm−3\mathrm{g\,dm^{-3}}gdm−3) | Rate after treatment at 25 ∘C25\ ^\circ\text{C}25 ∘C (mg min−1\mathrm{mg\,min^{-1}}mgmin−1) | Rate after treatment at 70 ∘C70\ ^\circ\text{C}70 ∘C (mg min−1\mathrm{mg\,min^{-1}}mgmin−1) |
|---|---|---|
| 5 | 0.80 | 0.00 |
| 10 | 1.40 | 0.00 |
| 20 | 1.90 | 0.00 |
The technician claims that increasing the lipid concentration can restore the activity of the lipase treated at 70 ∘C70\ ^\circ\text{C}70 ∘C.
Evaluate the technician's claim. Use the results and your knowledge of enzymes.
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.