WA: Life Science Update

This week the Life Science class did some graphing and data analysis.  They are working on cell processes and should have remitted their outlines with the vocabulary.  The class had an overview on the Science Fair rules.  They should have an idea for a project next week so they can begin work.  On Thursday, the students finished two graphing exercises and a CO2 lab.  How Cells Release Energy has a good explanation.

The CO2 lab involved cups, straws, and universal indicator; bromothymol blue is often used, too.  The students worked in pairs.  First, they measured 50 mL of water in plastic cups and added 10 drops of universal indicator with pH scales.  Initially, the water is green.  Each group used a stop watch and had a partner blow in the cup until the color changes.  The lab partner records the time for the color change to yellow, indicating the water has switched from a neutral pH to an acidic pH.  Each partner collects three trials.  Next, each group takes turn running in place for one minute before repeating the experiment three times.  The class averaged their times resting and running.  There are three questions: Why does the pH change?,  Why does the pH of the water change more quickly after running?, and What is the equation for cellular respiration?