Flour and Sugar Investigation with Carbon Dioxide Measurement and Vocabulary

1. Yeast InvestigationYeast Investigation
Investigation 3 - Part 2Investigation 3 - Part 2

2. • What are two most abundant
ingredients on cookie labels?
– Flour
– Sugar
• Something in cookie is food for yeast.
• Think of a way to find out what is in the
cookie that is food for yeast.
• Is one of the ingredients the food that
activated the yeast?

3. Flour/Sugar Investigation
• Mark one bag “F” and one bag “S”
• Add 2 5-ml spoons of yeast and 1 5-ml
spoon of flour or sugar to each bag
• Add 50 ml warm (40-50ºC) water to
each bag
• Press air out and seal bag.
• Place in hot water bath for 10 minutes
• Write prediction of what you think will
happen while waiting

4. Carbon Dioxide - CO2
• Cookie bag puffed - yeast produced a
gas when it became active
• Gas produced in Carbon Dioxide
• Same gas we exhale
• Amount of Carbon Dioxide produced is
indication of amount of activity taking
place in yeast cells

5. Volume Tube
• Used to measure volume of carbon
dioxide produced by yeast
• Carbon dioxide measured in milliliters
• Measure gas produced by flour and
sugar bags after 10 minutes
• Record results on chart

6. Cellular Respiration
• Yeast uses sugar as food source
• Plant and animal cells used sugar as
food source
• When cells use sugar - get energy and
produce carbon dioxide and water
• Process of breaking down sugar for
energy called Cellular Respiration
• Cellular Respiration breaks sugar into
carbon dioxide, water, and energy

7. Vocabulary
• Yeast - single-celled organism
• Cellular respiration - process by which
plant and animal cells break down
sugar to get energy, releasing carbon
dioxide and water in the process

8. Concepts
• What is cellular respiration?
– Cellular respiration is the process by which
plant and animal cells break down sugar to
get energy, releasing carbon dioxide and
water in the process
• C6H12O6 + 6O2→6CO2 + 6H2O +Energy