Part A. Making Visual Connections with the Textbook (5 points)
You can answer these in a Word document, indicating the question number followed by your answer.
Below is the Absorption Spectrum of Photosynthesis. As your textbook explains, plants have a number of light-absorbing pigments, including chlorophylls. These pigments absorb wavelengths of light depending on the chemical make-up of each pigment. Remember, these wavelengths have energy associated with them. When you measure how much light is absorbed over a range of wavelengths, you generate an absorption spectrum.
Figure 1 Absorption Spectrum of Photosynthesis
1. What color does chlorophyll appear to our eyes? What color would carotenoids appear to us?
2. The X-axis (horizontal) of the graph contains colors. What do those colors represent?
3. Does chlorophyll absorb much light of the wavelengths that correlate with the color you chose for chlorophyll? (For example, if you said chlorophylls appear violet to us, does chlorophyll absorb violet wavelengths to a great extent?)
4. What does your answer to Question #3 indicate about the colors we see? (Note: wavelengths are either absorbed by a substance or reflected back/transmitted through)
5. Based on Figure 1, if you wanted your plants to have maximal growth, what color(s) of light bulbs would you use?
6. As the diagram in your textbook suggests, “white” light is a mixture of all of the wavelengths of the visible portion of the spectrum. If you lived in a cold climate, what color should your roof be to maximize heat absorption? Explain.
7. Do the Calvin Cycle Reactions directly use sunlight? Explain.
8. Do the Calvin Cycle Reactions indirectly depend on sunlight? Explain.
9. If you did an Absorption Spectrum of Cellular Respiration for your cells, how similar to Figure 1 would it be?
Explain.
Part B. Connecting the Content (15 points)
This Activity asks you to compare and contrast Photosynthesis and Cellular Respiration by filling in the following figure (graphic organizer). Note that one page is “Compare” and one page is “Contrast.” Recall that “compare” means to find similarities, while “contrast” means to explore differences. List the item that you are comparing or contrasting in the left column, and then give the specifics in the next two columns. I have provided an example of a comparison in the first row. I encourage you to provide as many details as possible, since this activity is to help you learn the information. I have provided 10 rows but you can use more or less depending on what you need to completely address this Activity.
You can fill in the pages below and save them, along with your answers to Part A, to your computer and then attach the file in Blackboard.
Type Item for comparison
in the boxes below
Produce ATP
Light reactions Glycolysis, Krebs cycle, Electron Transport
Type Item for comparison
in the boxes below
You copied and pasted your entire test??
Part A. Making Visual Connections with the Textbook:
1. To determine the color of chlorophyll as it appears to our eyes, we can use the absorption spectrum graph provided in the textbook. By looking at the peak absorption wavelength, which is around 450-475 nm, we can conclude that chlorophyll appears blue-green to our eyes. Carotenoids, on the other hand, appear yellow to our eyes.
2. The colors on the X-axis of the graph represent different wavelengths of light, ranging from violet to red.
3. Chlorophyll absorbs light most effectively in the red and blue regions of the spectrum. So, if we chose chlorophyll to appear violet, it would not absorb violet wavelengths to a great extent. Instead, it would absorb more efficiently in the blue and red regions.
4. The absorption spectrum indicates that chlorophylls and carotenoids selectively absorb certain colors of light. The colors that are not absorbed are either reflected back or transmitted through the plants. Hence, the colors we perceive in plants are the ones that are not absorbed, but rather reflected/transmitted, by the pigments.
5. Based on Figure 1, if we wanted our plants to have maximal growth, we would use light bulbs that emit blue and red light. These are the regions where chlorophyll absorbs light most effectively.
6. If you lived in a cold climate and wanted to maximize heat absorption through your roof, you should choose a roof color that absorbs most of the visible light spectrum. This would include colors like black or dark brown. As the textbook suggests, white light is a mixture of all the wavelengths, and when light is absorbed, it is converted to heat energy. Dark-colored roofs would absorb more light and convert more of it to heat, thereby maximizing heat absorption.
7. No, the Calvin Cycle Reactions do not directly use sunlight. The Calvin Cycle is the part of photosynthesis that occurs in the stroma of chloroplasts and involves chemical reactions, such as the fixation of carbon dioxide and the production of glucose. It does not require direct input from sunlight.
8. Yes, the Calvin Cycle Reactions indirectly depend on sunlight. The energy needed to power the Calvin Cycle reactions comes from the light reactions of photosynthesis, which occur in the thylakoid membranes of chloroplasts. During the light reactions, light energy is absorbed by chlorophyll molecules, and this energy is used to generate ATP and NADPH, which are then used by the Calvin Cycle to produce glucose.
9. If you were to do an Absorption Spectrum of Cellular Respiration for your cells, it would be different from Figure 1. Cellular respiration is a process that occurs in the mitochondria and involves the breakdown of glucose to produce ATP. It does not have specific pigments that absorb light like photosynthesis. Therefore, an absorption spectrum of cellular respiration would not show distinct peaks at specific wavelengths like in Figure 1.
Part B. Connecting the Content:
Comparison:
1. Produce ATP:
- Photosynthesis: The light reactions of photosynthesis produce ATP through the process of photophosphorylation, where ATP is generated using light energy.
- Cellular Respiration: ATP production in cellular respiration occurs through glycolysis, the Krebs cycle, and the electron transport chain, which generate ATP through substrate-level phosphorylation and oxidative phosphorylation.
Contrast:
1. Energy Source:
- Photosynthesis: The energy source for photosynthesis is light energy, which is captured by chlorophyll pigments in the thylakoid membranes of chloroplasts.
- Cellular Respiration: The energy source for cellular respiration is organic molecules, such as glucose, which are broken down through various metabolic pathways.
Please note that there is space provided for more comparisons and contrasts in the graphic organizer. Feel free to add more items as needed to complete the activity.