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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Solace on October 12, 2018, 01:36:23 PM

Title: Colorimetry of Amylase metal ion inhibition (hydrolysis of starch) questions
Post by: Solace on October 12, 2018, 01:36:23 PM
Hey so I’m doing a design lab that looks at metal ion inhibition of amylase.
Currently I’ve been looking at three ions at different concentrations:
K+
Cu2+
Ag+
The amylase I have is yeast α-amylase plus reducing sugars— it refuses to dissolve by conventional methods.
The method basically consists of mixing a starch+iodine solution with amylase+inhibitor and quickly passing it to a colorimeter to get continuous absorbance data

The control run with no inhibition ran smoothly.
However I ran into a few problems when adding the inhibitors.
I realized that silver does not work because it forms a silver halide, so what can I use as a replacement as my “heavy” metal?
When adding copper ion to amylase it forms a kind of paste, which is what I assume is the denatured enzyme but when I mixed it with the starch solution it was too murky to get a reading from the colorimeter. I did not get to test the potassium.

So what can I do better, specifically how can get a mixture that is not too murky to get a reading?