Photosynthesis Carbon Dioxide Activity

Sadly, we were not able to acquire our own results during this investigation because the we were not able to observe much/any change in our specimens within the experiment. However, we were able to use previously found data from the same experiment to draw some conclusions. The jar directly under the lamp was dark purple, the jar being shaded from direct light was orange/red, and the jar placed in the cupboard was yellow.

These observations all make sense given what we know about photosynthesis. Photosynthesis happens at a faster rate when exposed to light; therefore, carbon dioxide was used faster in photosynthesis than it was being replaced during respiration causing the solution to turn a dark purple because the carbon dioxide was being reduced in the indicator. The solution in the jar that was thinly shaded from the light of the lamp turned orange/red because photosynthesis and respiration were happening around the same rate; therefore, the carbon dioxide in the solution was being replaced at the same rate it was being used causing the solution to reach an atmospheric carbon dioxide level. The solution of the jar placed in darkness turned yellow because photosynthesis was not taking place; therefore, no carbon dioxide was being used while respiration was producing more carbon dioxide, causing an increase in the carbon dioxide in the indicator solution.

These observations did very much confirm what we set out to show in this experiment.

The indicator turned yellow when the pondweed was placed in the dark.

We can deduce that the solution turned yellow because there was an increase in the carbon dioxide in the indicator solution. We can also deduce that there was an increase in carbon dioxide in the solution because photosynthesis was not taking place.

In our actual experiment, we think it may have been more beneficial to use a larger amount of pondweed from the very beginning of the experiment. We also think the experiment would have worked better if we had cut an inch down the stem of each piece of pond weed before moving the jars. We also think that using less of the indicator may have sped up the process.

The indicator would become yellow if I blew into it because I would be increasing the carbon dioxide in the solution.

The indicator would become red/orange is the plant were to respire and carry out photosynthesis at the same rate because carbon dioxide would be used at the same rate it would be replaced.

At mid-morning and in the afternoon, respiration and photosynthesis would occur at the same rate.

Photosynthesis Oxygen Activity

Bubbles Released At Various Lengths Over Time 

	1st 30 sec	2nd 30 sec	3rd 30 sec	Mean # of  Bubbles
Directly	29	28	27	28
6 in. away	20	20	19	19.6
12 in. away	13	12	13	12.6
36 in. away	8	7	7	7.3
No light	5	3	4	4

The independent variable in this experiment is the distance of the plant from the light while the dependent variable in this experiment is the number of bubbles released at any given distance. The control variable in this experiment is the number of bubbles released when the lamp was shut off. 

In my graph, the pattern shown is that the further the graduated cylinder got from the lamp, the fewer the bubbles produced over a thirty second time frame. Another pattern I began to notice is that the number of bubbles produced in the first thirty second trial tended to be greater than the number of bubbles produced in the third thirty second trial. 

The number of bubbles produced (the dependent variable) changes based on how close the plant in the graduated cylinder is to the light (the independent variable.) The amount of bubbles produced when there is no light from the lamp reaching the plant (the control variable) sets the basis for bubbles produced over a time period exposed to no/little direct lighting.

Because photosynthesis uses light to complete the process, it makes sense that the fewer bubbles released happened farther away from light exposure. We were slowly removing light; therefore, we were slowing the photosynthesis process every time we moved the plant further from the light slowing the rate of oxygen leaving the plant. 

The pattern shown in the graph does correlate with what I expected to happen. 

I feel as though one way we could have made this experiment more reliable is by performing the experiment in a darker room. If we had performed the experiment in a darker room, the direct lighting of the classroom would not have had an affect on the amount of bubbles released in any of the trials. The bubbles also were not the same size, meaning we didn't necessarily have a standard bubble size, we simply just counted all bubbles released. You may be able to measure the volume of gas being released by catching it in some sort of balloon (or something similar) and calculate the volume from there. 

I predict that the number of bubbles would increase if you increased the power of the light bulb. 

(The chart was complicated to copy and paste, and Blogger would not allow me to attach the cropped version of the chart.) 

Photosynthesis Oxygen Activity

Bubbles Released At Various Lengths Over Time 

	1st 30 sec	2nd 30 sec	3rd 30 sec	Mean # of  Bubbles
Directly	29	28	27	28
6 in. away	20	20	19	19.6
12 in. away	13	12	13	12.6
36 in. away	8	7	7	7.3
No light	5	3	4	4

The independent variable in this experiment is the distance of the plant from the light while the dependent variable in this experiment is the number of bubbles released at any given distance. The control variable in this experiment is the number of bubbles released when the lamp was shut off. 

In my graph, the pattern shown is that the further the graduated cylinder got from the lamp, the fewer the bubbles produced over a thirty second time frame. Another pattern I began to notice is that the number of bubbles produced in the first thirty second trial tended to be greater than the number of bubbles produced in the third thirty second trial. 

The number of bubbles produced (the dependent variable) changes based on how close the plant in the graduated cylinder is to the light (the independent variable.) The amount of bubbles produced when there is no light from the lamp reaching the plant (the control variable) sets the basis for bubbles produced over a time period exposed to no/little direct lighting.

Because photosynthesis uses light to complete the process, it makes sense that the fewer bubbles released happened farther away from light exposure. We were slowly removing light; therefore, we were slowing the photosynthesis process every time we moved the plant further from the light slowing the rate of oxygen leaving the plant. 

The pattern shown in the graph does correlate with what I expected to happen. 

I feel as though one way we could have made this experiment more reliable is by performing the experiment in a darker room. If we had performed the experiment in a darker room, the direct lighting of the classroom would not have had an affect on the amount of bubbles released in any of the trials. The bubbles also were not the same size, meaning we didn't necessarily have a standard bubble size, we simply just counted all bubbles released. You may be able to measure the volume of gas being released by catching it in some sort of balloon (or something similar) and calculate the volume from there. 

I predict that the number of bubbles would increase if you increased the power of the light bulb. 

(I apologize for the alignment of my data table; Blogger would not allow me to copy the table perfectly. The chart was also complicated to copy and paste, and Blogger would not allow me to attach the cropped version of the chart.)