Enzymes
Test how pH affects the breakdown of starch by the enzyme amylase.
Check your understanding with these quick common questions. Use the drop down boxes to see the correct answers.
Independent: pH of buffer solution.
Dependent: time taken for starch to be broken down.
Control: same enzyme concentration, temperature, starch volume.
Water bath, iodine in spotting tiles, stopclock, buffer solutions.
Keep temperature constant to ensure validity
Increase Accuracy of time taken by reducing the time between removing each sample. e.g. remove samples every 15 seconds.
Mix solutions well,
Repeat for reliability. .
Amylase works fastest at its optimum pH (around pH 7). Too high/low slows it down because the rate of reaction reduces and the enzymes start to denature.
Place amylase, starch, and buffer solution in test tube.
Keep in water bath at set temperature.
Every 30 seconds take sample, add to iodine on spotting tile.
Time how long until iodine stays orange-brown (no starch).
Repeat with different pH values.