Visit Your Local PBS Station PBS Home PBS Home Programs A-Z TV Schedules Watch Video Donate Shop PBS Search PBS
Scientific American Frontiers Logo
TV Schedule
Alan Alda
For Educators
Previous Shows
Future Shows
Special Features

Show title


 
Teaching Guide
Counting Calories
The Anti-oxidant effects of Vitamin C
Testing for Simple Sugars
Quiz
Educator Notes

QUESTIONS

  1. What happened to the appearance of the exposed apple surface without Vitamin C? (it turned brown)
  2. What caused this change? (oxidation)
  3. From where did this oxygen come from? (the atmosphere)
  4. Identify the substance that was "painted" onto the exposed apple surface. (aqueous solution of vitamin C)
  5. Did the vitamin C covering affect oxidation? (yes) How could you tell? (the exposed surface did not brown)


POOLING RESULTS
Pool the class results. Then, find the average time for a slice of apple to brown. Did your apple brown before or after the class average time? What might account for differences in the rate? (accept all reasonable answers such as different cut depths, different amounts of exposed surface)

CURRICULUM LINKS
 Chemistry:
  Chemical Reactions, Chemical Kinetics

NATIONAL SCIENCE STANDARDS (Grades 5-8)
 Science As Inquiry-Content Standard A
 Students should develop abilities necessary to do scientific inquiry,
 Students should develop an understanding about scientific inquiry
 Physical Science -Content Standard B
 Students should develop and understanding of the properties and   changes of properties in matter
  Students should develop and understanding transformations of energy

Back to Teaching Guide

return to show page

 

Doctor EmpathyObesity Begins at HomeCouch Potato KidsEat Less -- Live LongerThe Desert's Perfect Foods Teaching guide Science hotline video trailer Resources Contact Search Homepage