An enzyme catalyses the breakdown of maltose into glucose. Its optimum temperature is 35 ∘C35\,^\circ\mathrm{C}35∘C.
Equal samples of the enzyme were kept at different temperatures for five minutes. Each sample was then cooled to 35 ∘C35\,^\circ\mathrm{C}35∘C and mixed with maltose of the same concentration and volume.
| Treatment temperature (∘C^\circ\mathrm{C}∘C) | Rate of glucose production (mg min−1\mathrm{mg\,min^{-1}}mgmin−1) |
|---|---|
| 35 | 4.8 |
| 45 | 4.6 |
| 55 | 2.0 |
| 65 | 0.2 |
Explain why samples treated at higher temperatures produced glucose more slowly after they were cooled.
A separate enzyme sample is treated at 65 ∘C65\,^\circ\mathrm{C}65∘C and then cooled to 35 ∘C35\,^\circ\mathrm{C}35∘C. It is left at this temperature for a further 20 minutes before maltose is added.
Suggest the rate of glucose production and explain your answer.
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.