The Crime Scene Crime scene Bakery Victim Yeast
The Crime Scene Crime scene: Bakery Victim: Yeast At the scene, three unknown compounds were found next to the victim - Compound A - Compound B - Compound C It is your job to identify these compounds © 2008 Society of Toxicology
How to identify the unknown compounds • We will use yeast as a model system to test the compounds • Each group will be assigned to two compounds (A, B or C) to test – Perform a dose response with your compound and compare to a control (no compound) – Compare your dose response to known compounds © 2008 Society of Toxicology
Yeast as a model system Yeast + water + sugar + O 2 If yeast are healthy, they will produce a great deal of CO 2 and the balloons should inflate What if the yeast are not healthy because something toxic has been added? © 2008 Society of Toxicology CO 2 + alcohol
Instructions LATEX allergies? ? ? Please notify your team toxicologist Add sugar water to your tubes Add appropriate number of drops of unknown compounds and mix (wear gloves, do not smell, take care not to spill) Add yeast (3 mini-spoonfuls), using the funnel Cap and Mix (by shaking) Secure balloon (with elastic, center the base) Incubate 15 -20 minutes at heat source Measure circumference of balloons Control= Orange Compound A=Pink Compound B= Yellow Compound C= Red © 2008 Society of Toxicology
Clean up • Return the following items to the plastic bag and give it to your Team Toxicologist Yeast jar Funnel Marker Un-used stirring “sticks” Test tube tray and measuring tape- when you are done The rest of the items can be discarded © 2008 Society of Toxicology
Things to think about What if the water was too hot or cold? Why do we need controls? What could we have added to give ourselves more confidence in our results? What are some variables of this experiment that can impact the way we interpret our results? What do you think killed the yeast? How do we know our experiment worked? If it didn’t work, what could be the problem? + © 2008 Society of Toxicology +
Questions to Consider What compound is the most toxic? How can you tell? Which compound do you think was used to kill the Yeast, based on overall toxicity? Are there differences between the curves generated by the students, and the curves generated by the lab? If so, Why? Are there differences in the amount of carbon dioxide generated by the controls? • 7 Society of Toxicology © 2008
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