Effect of pH on Enzyme Activity

1. 1. 1. Add 5 ml of water to an empty tube (this is the BLANK)
      2. To 3 separate tubes, add 2.5 ml of buffer pH 3, pH 5 or pH 7
         1. Add 2.5 ml of starch (substrate) to each of these tubes (excluding BLANK)
      3. Add 2 drops of iodine to each tube and mix: Blank, pH 3, pH 5, pH 7
      4. Read the Blank in the spectrophotometer and calibrate it to 100% transmittance at 560nm
      5. Read each tube in the spectrophotometer. This is time 0 min.
      6. Add 35 drops of amylase solution to each tube simultaneously, mix to homogeneity.
      7. At 2 minute intervals, quickly read ALL tubes in the spectrophotometer.
      8. Continue reading the samples every 2 minutes until you reach 22 minutes on the table below.

Time (min)	pH 3 % Trans	pH 5 % Trans	pH 7 % Trans
0
2
4
6
8
10
12
14
16
18
20
22

Tags: quantitative reasoning, analysis, inquiry, integration of knowledge