If you did not finish this by the due data (23 Jan), attempt this a second time, any correct answers will be saved in your second attempt.
This lab is divided into two grades:
Q1-5 (the data)
Q6-10 (post-lab questions)
If you did not finish this by the due data (23 Jan), attempt this a second time, any correct answers will be saved in your second attempt.
This lab is divided into two grades:
Q1-5 (the data)
Q6-10 (post-lab questions)
Green plants use light energy to produce their own food using photosynthesis. You may have already learned that plants require water and carbon dioxide and light for photosynthesis and that the process produces oxygen and glucose (a sugar - the food for the plant). If one of those three inputs (water, carbon dioxide, or light) is in short supply, then photosynthesis will slow down or even stop.
Light intensity is a measurement of the amount of light received in a given area (often a square meter, m2, in a given amount of time. The intensity of light can be affected by increasing or decreasing the angle the light source is from an object, or increasing or decreasing the distance a light source from an object. In both cases, if either is increased, the intensity of light is decreased; and if either is decreased, the light intensity is increased. Thus, it can be said that both of these variables (distance and angle) have an inverse relationship with light intensity — as one increases, the other decreases.
Wavelength of Light - The wavelength of light is a measurement of the energy of light. White light (the type of light we typically experience from the sun and artificial lights) has many wavelengths, from 400 nm to 700 nm. These wavelengths also align to the visible spectrum (sometimes referred to as a "rainbow"), with each color in the spectrum have their own specific wavelengths.
Color | Wavelength (nm) |
|---|---|
Red | 625 - 750 |
Orange | 590-625 |
Yellow | 565-590 |
Green | 500-565 |
Blue | 485-500 |
Indigo | 450-485 |
Violet | 380-450 |
The shorter the wavelength (the lower the number), the higher the energy of the light and the longer the wavelength (the higher the number), the lower the energy. Like with light intensity, light angle, and light distance, the wavelength and energy also have an inverse relationship.
By analyzing data from a classic lab experiment we can draw some conclusions about the effect of light intensity (or strength) as well as the wavelength of light on photosynthesis.
The two variables that will be tested in this lab are the light intensity and wavelength, we will use the amount of oxygen produced in 30 minutes to measure how changing these variables will impact the rate of photosynthesis.
Part 1 - Light Intensity
(this data will be transferred to a Google Sheet to make a graph)
Distance (cm) | [Oxygen] at 30 min |
|---|---|
0 | |
10 | |
20 | |
30 | |
40 | |
50 | |
60 | |
70 | |
80 | |
90 | |
100 |
Part 2 - Specific Spectra
(this data will be transferred to a Google Sheet to make a graph)
Wavelength (nm) | [Oxygen] at 30 min |
|---|---|
390 | |
410 | |
430 | |
450 | |
470 | |
490 | |
510 | |
530 | |
550 | |
570 | |
590 | |
610 | |
630 | |
650 | |
670 | |
690 |
Open the following Google Sheet - https://docs.google.com/spreadsheets/d/10O5-dXJOUI-CQOSsmvcBusKY0WpQlOeuN6JecMeS8h0/copy
It is titled, "Dynamics of Photosynthesis Data".
When you make a copy, add your name to the front of the title.
Example: "J. Poe Dynamics of Photosynthesis Data"
Make sure a copy is made.
It's supposed to do this automatically.
If not, in the upper-left of the Sheet, click, "File" then, "Make a Copy".
Transfer the data from Part 1 and Part 2 onto the the corresponding data tables on the "Dynamics..." Sheet.
When you input the data in each table, a line graph will begin to form next to each table. You will submit a screen shot of each just prior to the post-lab questions.
Copy and past a copy of your line graphs created on the "Dynamics of Photosynthesis Data" Sheet.
You must post a line graph for Part 1 and Part 2 - two total line graphs.
I must regrade this.
Green plants use light energy to produce their own food using photosynthesis. You may have already learned that plants require water and carbon dioxide and light for photosynthesis and that the process produces oxygen and glucose (a sugar - the food for the plant). If one of those three inputs (water, carbon dioxide, or light) is in short supply, then photosynthesis will slow down or even stop.
Light intensity is a measurement of the amount of light received in a given area (often a square meter, m2, in a given amount of time. The intensity of light can be affected by increasing or decreasing the angle the light source is from an object, or increasing or decreasing the distance a light source from an object. In both cases, if either is increased, the intensity of light is decreased; and if either is decreased, the light intensity is increased. Thus, it can be said that both of these variables (distance and angle) have an inverse relationship with light intensity — as one increases, the other decreases.
Wavelength of Light - The wavelength of light is a measurement of the energy of light. White light (the type of light we typically experience from the sun and artificial lights) has many wavelengths, from 400 nm to 700 nm. These wavelengths also align to the visible spectrum (sometimes referred to as a "rainbow"), with each color in the spectrum have their own specific wavelengths.
Color | Wavelength (nm) |
|---|---|
Red | 625 - 750 |
Orange | 590-625 |
Yellow | 565-590 |
Green | 500-565 |
Blue | 485-500 |
Indigo | 450-485 |
Violet | 380-450 |
The shorter the wavelength (the lower the number), the higher the energy of the light and the longer the wavelength (the higher the number), the lower the energy. Like with light intensity, light angle, and light distance, the wavelength and energy also have an inverse relationship.
By analyzing data from a classic lab experiment we can draw some conclusions about the effect of light intensity (or strength) as well as the wavelength of light on photosynthesis.
The two variables that will be tested in this lab are the light intensity and wavelength, we will use the amount of oxygen produced in 30 minutes to measure how changing these variables will impact the rate of photosynthesis.
What are the two products of photosynthesis?
In this lab, we used the amount of oxygen produced to indicate the rate of
In this lab, if the oxygen production was high, the rate of photosynthesis was
If the oxygen production was
Refer to the Part 1 data.
At what distance was the rate of photosynthesis the highest?
Cite the data for 7a. How do you know your answer to 7a is correct?
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Refer to the Part 1 data.
At what distance was the rate of photosynthesis the lowest?
Cite the data for 7c. How do you know your answer to 7c is correct?
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Use Part 2 Data.
In a chloroplast, only light that is absorbed will result in photosynthesis.
From the Part 2 data, how do you know if a specific wavelength of light was absorbed well by the chloroplast?
Use Part 2 Data.
In a chloroplast, only light that is absorbed will result in photosynthesis.
From the Part 2 data, how do you know if a specific wavelength of light was NOT absorbed well by the chloroplast?
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Refer to Part 2 data.
Were all wavelengths of light absorbed well by the chloroplast?
Cite your data from Part 2. How do you know your answer to 9a is correct?
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Cite your data. Create a list, from the lowest to the highest, which wavelengths of light were absorbed the most (notice that is does not say, which one wavelength was absorbed the best)? Which colors of the spectrum do they align with (review the reading at the top of this)?
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Cite the data. How do you know your answer to 9c is correct.
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Review the data from part 1 and part 2.
Photosynthesis is the conversion of carbon dioxide and water into glucose and oxygen by using light energy to drive the reactions in the chloroplast.
If a plant is exposed to light, will it always perform photosynthesis at a high rate? How do you know? In your answer, explain how specific points of data from both parts of this lab supports your ideas.
This is the largest scoring question that is supposed to be a culmination of this whole lab. I will grade it in accordance with that fact - be inclusive with the data and draw relevant conclusions from it (think about the class discussion of the two graphs).
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What happens to light intensity as the light moves closer to the plant?
What happens to light intensity as the light moves father from the plant?
According to the data for Part 1, what happened to the rate of photosynthesis as the light intensity increases (be sure to explain how you know)?
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According to the data for Part 1, what happened to the rate of photosynthesis as the light intensity decreases (be sure to explain how you know)?
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