Photosynthesis

Photosynthesis Dry Lab

In this “dry lab” you will be working backwards from what you would normally do in a lab situation. In this case, you will be given a set of observations that were made in a lab and you will be asked to reconstruct the procedure that could have generated this data. You will also be given a set of facts that you will use to explain this set of observations in the analysis and conclusions section of your lab write-up. As you create the procedure for this lab, please remember all the rules that you have been learning about good experimental design.

Your lab report begins below. Fill in the missing sections of the lab report using the observations and facts given. You may assume that you have access to as many test tubes, snails, Elodea plants, light sources, dark places, and as much pond water and BTB as you need.

Make your own copy of this Google Doc and edit the lab report that begins here:

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My Most Awesomest Photosynthesis Lab Report

by

Question(s):

Background Research Facts About Photosynthesis and Respiration:

• Carbon dioxide in water produces carbonic acid.
• Bromothymol Blue (BTB) is a blue-green liquid which changes to a yellow color in acid and back to blue-green when returned to a neutral pH.
• Carbon dioxide plus water yields sugar and oxygen when chlorophyll and sunlight are present.
• Animals respire.
• Green plants photosynthesize in the light and respire all the time.
• Sugar plus oxygen yields carbon dioxide plus water and energy.

Materials:

1. water

2. blue Btb

3.beaker

4.snail

5.plant 

Procedure:

1. put room temperature in beaker
2. put four drops of btw in beaker with water 
3. stir the beaker till btb is mixed with the water
4. put a snail in beaker that has water and blue btw
5. then follow step 1,2,3 with a new beaker
6. put plant in the new beaker 

Results/Evidence:

1. Water plus bromothymol blue is blue-green.
2. Water plus bromothymol blue plus an aquarium snail turns yellow.
3. Water plus bromothymol blue plus Elodea (an aquarium plant) is blue-green in light.
4. Water plus bromothymol blue plus a snail plus Elodea is blue-green in light and yellow when left in the dark for three hours.

Analysis of Results (use your Research Facts to explain each result):

1. Water plus bromothymol blue is blue-green because... bromothymol (btb) is a blue looking liquid which later turns into a yellowish color in acid and back to blue- green when returned to a neutral ph

2. Water plus bromothymol blue plus an aquarium snail turns yellow because... when you put a snail in water then the acid of the snail and the carbon dioxide react with btb which changes to yellow

3. Water plus bromothymol blue plus Elodea (an aquarium plant) is blue-green in light because... when you put the plant elodea in some water it turns to blue-green

4. Water plus bromothymol blue plus a snail plus Elodea is blue-green in light and yellow when left in the dark for three hours...