Amylase Action

Ohhhh boy, today's lab was... interesting.


We usually don't do labs on Wednesdays because we only have a half an hour before PE, and my class takes longer than that to do labs.  But today's lab didn't seem like it would take all that long.  Yesterday we went over what to do so they could get started right away today. 


Here's the basic outline of the lab: Spit saliva into a cup, put bread in it, stick it in the fridge.  Do the same but leave the cup in room temperature.  While they're sitting for a half an hour, take a piece of bread, chew it for 30s, another for 1min, another for 2-3min.  Then drip iodine on them to see how much starch is in them. 


There's an enzyme in saliva that cuts starches into little glucose molecules, so theoretically, the iodine shouldn't have turned the bread dark (because the saliva would've been breaking it apart).  We didn't exactly get those results...


My class was completely grossed out.  Like, they couldn't even put the bread in their mouths because it was too gross to think about, let alone chew and spit it out.  This completely surprised me.  They love talking about gross stuff in class!  And now when it comes time to do a gross/cool experiment, they flake out on me.  A few kids looked like they were going to throw up; one claimed he actually threw up in the garbage.  A few got white and asked if they could stand by an open window to get air.  Enough of them were freaking out that I actually passed out ice cream pails to each group, just in case. 


It was crazy!  They were complaining about how gross this lab was and how they didn't want to do it... we did finally get the lab done, but they didn't keep the bread in their mouth long enough, so it didn't really work.  Disappointing.  And the 6th graders were in an uproar because the now 8th graders didn't have to do it when they were in my class (this is the first year we're doing this curriculum). 


Anyway.  We went over to church right after school to set up for our Lenten supper.  Now it's time to head back over and check up on things.  Hopefully we get a good turnout!  It's been really windy today and kind of gross... so I'm guessing a bunch of people are going to stay home.