Amylase, Starch, pH

[JerriBlank]

I am so confused. I'm working on my research project: The effect of pH level on the efficiency of the enzyme amylase. My teacher is no help.

I have set up my experiment, with pH levels of 1, 4, 7, & 10. 1 & 4 produce dark blue solutions, while 7 & 10 produce clear solutions(although, I was absent for a few days and the 7 & 10 might need to be redone, so you can disregard that).

Maybe I'm mixed up, but at a low pH, shouldn't starch + amylase + iodine produce a clear solution (starch broken down), and blue solution at higher pH's (starch present). We have a log book check tomorrow. Yikes.

Thank you for any help!

[kjle]

I believe there are different types of amylase. One of them being salivary amylase which breaks down starch in your mouth, which has a very slight basic, or neutral pH. THere is also a pancreatic amylase which breaks down starch in the duodenum. Here the pH is lower. This may be where your confusion lies.

Please correct me if I am wrong. Hope this helps.

[JerriBlank]

I believe you are right. I also believe I'm using salivary amylase, though my teacher won't tell me for sure. He's a bit distracted, the most specific answer I could get out of him about what type of amylase I was using was "in solution form."

Granted I'm not a genius, but I had already gathered that much. My results are still backwards though, with breakdown at pH's of 7 and 10 and no break down at 1 and 4. Sigh.