Class Notes for Monday, July 2, 2007

cell membrane differences activity:

• tennis ball can cut into 3 sections
• mixture with sand, salt, marbles, bb's
• give 3 filters - strawberry basket, window screen, filter paper, etc. Ask them how they can assemble a device that will separate each type

Making Your Own Indicator Solution:

• 3 mL bromolthymol blue and fill with tap water to make 250 mL of solution
• take a plastic cup and add about 2 inches of solution. Use straw and white piece of paper. Blow into liquid until you see something happening!
• what is happening? air? co2?
• can turn back to blue if you put air in it!
• blue is about 7.2 pH
• 7 is green
• 6.8 and below is yellow
• if you used distilled water, it will START as yellow. pH of distilled water is about 5.0, because the way distilled water is made, it is exposed to a lot of air and so CO2 will diffuse in
• when you make the solution, watch out because each tap can produce water of different pHs... even in the same building!
• when turns yellow, to turn BACk to blue, just use a few specks of baking soda.
• NaHCO3 = sodium bicarbonate = baking soda

NaHCO3 -> Na+ + HCO3
HCO3- + H+ <-> H2CO3<->H2O+CO2

PHOTOSYNTHESIS

6CO2 + 6H2O + E <--> C6H12O6+6O2

Can use water snails and elodea to make experiments, however only with brom. blue, Phenol red is TOXIC! and must add tap water conditioner to negate cloramine for snails.

4 test tubes - all 4 with blue in it. 2 are breathed into to turn yellow. In one of the yellow, place elodea - the other remains empty for control. in one blue, place another plant - the other blue is the 2nd control.

Respiration - "Feel The Burn"

• Hand Sprints - all the way open, all the way closed.
• count how many you do for 20 seconds, go again!
• arms feel hot, out of breath, etc. Oxygen stops going to arm muscles, so to get energy, have to do lactic acid fermentation (why you feel burn) BUT doesn't produce as much energy as cellular respiration with O2
• cellular pH actually does decrease! acid denatures proteins
• cellular respiration happens in mitochondria. Once no more oxygen, mito shut down, basically are not working anymore. Anerobic (without oxygen) happens in the cytoplasm of the cell