Low Cost Bology Experiments

Anthony Tomlinson tomlinson at pplros.demon.co.uk
Fri Oct 4 11:13:50 EST 1996


In article <40.10123.3126 at channel1.com> Harold Drabkin,
harold.drabkin at channel1.com writes:
>For the higher grades, one might consider using the action of salivary
>amylase to demonstrate enzymes.  Simple starch solution for substrate;
>iodine solution for a color development to show up the starch; saliva
>for the enzyme source.  One could do simple things like heat
>denaturation, etc. (I used to do this with a group of high school
>sophomores; I had access to a spec. 20, so we could even get some
>numbers, but this isn't absolutely necessary).

Here's a similar one, to demonstrate reduction of hydrogen peroxide by
the enzyme
catalase.  Grind up fresh liver, drop it in H2O2 (chemists sell it) and
hey
presto! O2 is given off, which will relight the proverbial glowing spill.
You can do the same enzyme denaturation stuff on it, and if you have a
gas syringe
maybe even measure activity/gfw. 

You can demonstrate transpiration with shoots (celery, for example) in
water,
sugar, etc, block it with vaseline, increase rate with airflow, and
monitor it
in light and dark etc (I'm less clear on this one, but it worked in 2ndary
school!).  Just cut the stems underwater to avoid air bubbles in the
xylem.

Osmosis can be shown with potato slices in water and saturated sugar
solution.

That's all I can come up with for now, but watch this space!


Anthony



More information about the Bioforum mailing list