Photosynthesis Lab Inquiry 20131

8/10/2019 Photosynthesis Lab Inquiry 20131

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Name: David Pham Date: 12-8-13 Period 5

How Is Carbon Cycled?

Write the chemical equation for photosynthesis (you already know thisupside down and backwards!!):

6H20 + 6CO2 + Sunlight --------------> C6H12O6 + O2

What ingredients do autotrophs need in order to produce glucose?

Autotrophs need water, sunlight, and carbon dioxide to produce glucose.

How will you set up four test tubes to provide evidence of how carbon is cycled?

Independent Variables: The amount of elodea plants or snails in each test tube

Dependent Variable: The amount of CO2 and color of solution.

Procedure:

1. Create BTB solution by covering the bottom of a flask and filling it with 150 ML of distilled water.

2. Add materials or independent variables to the test tubes.

3. fill each tube to the top and make it airtight by using a stopper

4. Acquire lamp or any light source and shine it at the test tubes

5. Observe color of the BTB solution for each tube and record data.


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Hypothesis:Predict what will happen in each test tube by shading the color you think the bromothymol blue in the

tubes will be in 24 hours. Include which independent variables will be applied in each tube by using text or illustration.

Then explain why you think the test tube will be the color you think. Finally, use color to shade in the tube.

If then. Because:

Test Tube 1 1. Contains only BTB solution

2. If nothing is added to the tube except for BTB then the color of the BTB solution

will stay blue and will not change at all because no CO2 will be created.

Test Tube 2 1. Contains elodea plant

2. If elodea plant is added to the tube, the BTB solution will turn blue because

photosynthesis will convert CO2 into O2.

Test Tube 3 1. Contains aquatic snail

2. If aquatic snails are added to the tube, the BTB solution will turn yellow because

cellular respiration will convert O2 into CO2

Test Tube 4 1. Contains both elodea and aquatic snail

2. If elodea and aquatic snails are added to the tube, the BTB solution will turn green

because cellular respiration and photosynthesis are both occurring. The elodea

uses CO2 and produces O2. The snail uses O2 and produces CO2. As a result, the

level of CO2 will stay balanced.

Design a Data Table Below to organize your data:

Title ____________________The tubes of Life and Carbon__________________________


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Test Tube Contents of each tube Hypothesized color Actual Color

1 Nothing

2 Plant

3 Snail

4 Plant and Snail

1. Test tube one did not change color because no CO2 could enter or leave the tube. No organisms produced or used up any CO2

2. Test tube 2 turned dark blue because the level of CO2 was very low. This is because the plants use photosynthesis. This takes

up CO2,water, and sunlight and turns it into O2 and glucose. As a result, the level of CO2 got low because of the plant using

photosynthesis.

3. Test tube 3 turned yellow because the level of CO2 was high. The snails use cellular respiration. in this process, O2 and glucose

is converted to CO2, H20, and energy. Since the snails used O2 and made it into CO2, the level of CO2 was high. As a result, the

color of the BTB turned yellow.

4. Test tube 4 turned into light blue because the level of CO2 was moderate. This was because of the plant and snails. The plant

used photosynthesis and the snails use cellular respiration. Photosynthesis from the plant uses up CO2, H2O, sunlight and

turns it into glucose and O2. Cellular Respiration from the snail uses up O2 and glucose and converts it into energy, H2O, and

CO2. Since photosynthesis and cellular respiration has CO2 on opposite sides of the equation, the level of CO2 is balanced. The

snail uses O2 and creates CO2 and plant uses CO2 to make O2. As a result, the plant fuels the snail and the snail fuels the plant

Carbon is cycled through plants and animals. Plants use photosynthesis and animals use cellular respiration. In tube one, no organisms

were in the tube so carbon was not cycled. We know this because the color of the BTB did not change color. This signified that the level

of CO2 stayed the same and did not change. However, in tube 4, there was a snail and a plant. This meant that photosynthesis and

cellular respiration was going on at the same time. As we all know, photosynthesis from the plant uses up CO2, H2O, sunlight and turns

it into glucose and O2. Cellular Respiration from the snail uses up O2 and glucose and converts it into energy, H2O, and CO2. Because

photosynthesis and cellular respiration contain CO2 on opposite sides of the equation, the level of CO2 is balanced. The plant uses the

CO2 produced from cellular respiration (the snail) and the snail uses O2 produced by photosynthesis (the plant). All in all, the plant fuels

the snail and the snail fuels the plant.

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Photosynthesis Lab Inquiry 20131