O-LevelBiologyEnzymes5090/11 · Oct/Nov 2011 · Q41 Mark
The diagram shows an experiment on amylase. Each beaker contains water at the temperature shown. After five minutes, each test-tube of amylase is poured into the test-tube of starch solution in the same beaker. After leaving the tubes for 5 minutes, samples of the mixture are tested with iodine solution and are then tested again at 5 minute intervals. Which results are expected? [Figure 4.1]
This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.
A90°C: blue-black after 30 minutes; 35°C: goes yellow-brown immediately; 20°C: goes yellow-brown after 5 minutes; 10°C: blue-black after 30 minutes
B90°C: blue-black after 30 minutes; 35°C: goes yellow-brown after 5 minutes; 20°C: goes yellow-brown immediately; 10°C: blue-black after 30 minutes
C90°C: goes yellow-brown immediately; 35°C: goes yellow-brown after 5 minutes; 20°C: goes yellow-brown after 5 minutes; 10°C: blue-black after 30 minutes
D90°C: goes yellow-brown after 5 minutes; 35°C: blue-black after 30 minutes; 20°C: blue-black after 30 minutes; 10°C: goes yellow-brown after 5 minutes
✓ Correct answer
A: 90°C: blue-black after 30 minutes; 35°C: goes yellow-brown immediately; 20°C: goes yellow-brown after 5 minutes; 10°C: blue-black after 30 minutes
Practise more questions on this topic
Oracle Prep sorts past-paper questions by topic, so you can drill Enzymes and see which topics are most likely to come up next.
Sign up free →