Each TABLE will make one recipe, enough for TWO Petri dishes We will be using water from the tap (no distilled water this time)
Goggles, as usual When working with the beakers of water, use tongs to put them ON and OFF of the hot plate Why? PLEASE PUT BOILING BEAKER ON BENCH Bench is tough – can take it DO NOT ADD ANY CHEMICALS TO THE WATER UNTIL IT IS ON THE BENCH!
Purpose: Which laundry soap will dissolve the Jell-O the best Research: What are enzymes and how do they/can they affect living tissue? What is gelatin? Hypothesis: I believe that ___________ will dissolve the Jell-O the best.
Wait until boiling water (in beaker) is on bench top For weighing out chemicals, first place the weigh boat on the scale then ZERO it out 18 g regular Jell-O/1.8g sugar-free Jell-O 0.7g Na 2 CO 3 Gently stir in chemicals (with the stir rods) Wait until mixed, then pour equal amounts into two Petri dishes Label Petri dish with your names! Clean up!
Make 7 wells in your Jell-O using a straw Measure the diameter of your wells using mm and record Using a pipette and 6 different diluted detergents (10mL liquid w/90mL water OR 10g solid w/90mL water), add 1 detergent to each well (about 2-3 drops): MAKE A DIAGRAM TO REMEMBER WHICH DETERGENT IS IN WHICH WELL In the 7 th well you will add water to act as a(n) _______________ Control Cover, set aside and wait 24 hours
Suction out the dissolved Jell-O with a pipette and discard Draw a picture of the Petri dish making sure to concentrate on the quality (qualitative) of the Jell-O surrounding the wells as well as the amount of Jell- O that appears to be dissolved (quantitative- measure the new diameter in mm and record) Rank the liquids (detergents) in the wells from 1 (best) to 7 (worst) in terms of their digesting ability Discard the Jell-O/wipe out the Petri dishes Answer the remaining questions on your hand out (due Monday)