Human Bio: Enzymes

Update: Anna set up the experiment with the yeast spheres and hydrogen peroxide.  She diluted 3% H2O2 to 1.5, 0.75, and 0.375% concentrations.  The H2O2 was at room temperature for the first series.  She timed how long it takes for the yeast sphere to rise to the top of the test tube.  The  she repeated the same test with the same concentrations in boiling water and ice water baths.  Anna is writing up this lab with information about the importance of enzymes in the human body.  I'll post her report when she finishes. 


I was looking for interesting labs for Anna to do today after she weighed the remaining sweet potato cubes for the previous osmosis lab.  I came across Catalase Activity in Immobilised Yeast or Exploring Catalase and Invertase Activity.  We used the procedures in the Catalase Activity in Immobilised Yeast.  I had yeast, hydrogen peroxide, sodium alginate, and calcium chloride on hand.  You need a syringe, too.  (Calcium chloride is Driveway Heat.  I used baker’s yeast and 3% hydrogen peroxide from Walmart.  The sodium alginate was ordered from Amazon.  I had the yeast and peroxide on hand from Elephant’s Toothpaste kid lab and the sodium alginate I had ordered to refill Fizz Wizz and Jammin Jelly.).

Today was practice.  I had done catalase experiments before—none with yeast spheres.  Anna made up the yeast, sodium alginate, and calcium chloride solutions according to the instructions.  We suspended the syringe 20cm above the beaker with calcium chloride.  After Anna practiced dropping the yeast suspension, she made uniform spheres.  We did a quick trial with the yeast sphere, by dropping it into 3% peroxide in a beaker.  One drops the sphere into the peroxide beaker and times it to see when the sphere rises to the top of the peroxide.  Next time, Anna is going to make fresh solutions, fresh yeast spheres, and hydrogen peroxide dilutions to test.  She’s also going to test the yeast in different temperature baths and with different pH concentrations.

After she finishes, we’ll review catalase, enzymes, concentration units, and the effect of different factors, temperature, pH, concentration of peroxide has on enzyme activity.

                                         
                                            Note the syringe is about 20 cm above the beaker.

                                                      These are the first spheres.

                                                  Look how uniform they are!