CAPE Biology Unit 1 · 2007 (Specimen) · Paper 1 · Question Q13
Amylase found in germinating seeds is incubated with starch at 25^\circ\text{C} and pH 2. When a sample is removed after five minutes and mixed with a solution of iodine in potassium iodide solution, the mixture turns to a blue-black colour. The MOST likely explanation for this observation is
- (A)all the starch has been hydrolysed to maltose
- (B)a specific inhibitor of the amylase is present
- (C)amylase does not catalyse the hydrolysis of starch at
25^\circ\text{C} - (D)the pH is too low for the reaction to proceed quickly
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