PH and enzyme Prac.

• control variable is adding 1 drop of iodine into spotting tiles with pipette
• add 2cm cubed of PH buffer and amylase into test tube
• mis PH and amylase solution with starch in measuring cylinder.
• to change PH of enzyme add PH buffer to amylase .
• starch turns iodine to a blue black colour
• after 20 seconds add a drop to the next well and repeat until starch doesn't turn iodine blue-black
• yellow means starch has broken down