Photosynthesis Internet Activity Name: Biology Date: Period: A. Illuminating Photosynthesis Site: http://www.pbs.org/wgbh/nova/nature/photosynthesis.html Directions: Read the Introduction “Illuminating Photosynthesis” By Rick Groleau Click on the link “Launch Interactive” and read the introductory poem. Click on “The Cycle” at the top of the box. 1. Click on each of the following items, and explain what happens: a. The shade over the window: b. The container of water: c. The child: 2. a. What gas does the child provide for the plant to use? b. What gas does the plant provide for the child to use? c. Will the plant continue to produce this gas if the shade over the window is closed? (Try it to see) 3. According to this animation, what 3 main things does the plant need for photosynthesis to occur? 1.) _________________________________ 2.) _________________________________ 3.) _________________________________ Click “The Atomic Shuffle” at the top of the box, read the introductory poem, & click “next.” 4. What type of molecule is shown in the leaf? ________________________________________ 5. Draw one of the molecules below, as it is shown in the leaf. 6. According to the reading, these molecules “do not come from the tap.” What 2 places do they come from? 1.) _______________________________ 2.) _______________________________ Click “next” and watch carefully. You may click “replay” to watch again. 7. a. What is “stripped” from each water molecule? b. From where does the cell get the energy to do this? c. The stripped molecules form pairs. Where does it go after this? 8. Click “next” What gas enters the leaf? This gas enters through “holes” in the leaf. What are they called? 9. Click “next”. What molecule is formed once again? 10. Click “next”. Another molecule is formed (“and boy it is sweet”). Draw and name this molecule below as shown. Click “Three Puzzlers” at the top of the box. 11. Answer each of the following questions, and explain in your own words. a. Can a tree produce enough oxygen to keep a person alive? Explain. b. Can a plant stay alive without light? Explain c. Can a plant survive without oxygen? Explain. B. Factors that affect the rate of Photosynthesis Introduction: In this simulation, you will be looking at the production of oxygen as a plant photosynthesizes. This procedure can be accomplished by placing elodea plants in water with baking soda to provide carbon. The plant can then be exposed to varying intensities and colors of light. Oxygen is measured in the number of bubbles produced by the plant. This simulator addresses three factors that influence the rate of photosynthesis. Carbon dioxide availability, light intensity, and light color can all be adjusted in the simulator to determine how each of the factors affects the rate of photosynthesis. Goal: 1. Determine the factors that affect a plant ability to photosynthesize 2. Determine the optimal conditions needed for photosynthesis Site: http://www.biologycorner.com/flash/waterweed.html Questions 1. In this investigation, how will you measure the rate of photosynthesis? 2. Why would this procedure not work with a terrestrial plant? Question 1: How does the color of light affect the rate of photosynthesis? Directions: 1. Set the run speed to x5 2. Set the light level to 5 3. Set the CO2 level to 5 4. Run each filter color 3 times and average the result Filter Color Count Run 1 Run 2 Run 3 Filter Color Count Run 1 Run 2 Run 3 Average = Filter Color Run 1 Run 2 Run 3 Average = Count Filter Color Count Run 1 Run 2 Run 3 Average = Average = Bubble number Effect of Light Color on Photosynthesis Light Color 1. What color(s) of light do plants absorb to photosynthesis (white is not a color of light)? Explain. 2. What color(s) of light do plants not need for photosynthesis? Explain 3. If white light contains all the colors of light (ROY G BIV) why did white light produce the most bubbles? 4. If you had to design a light that only produced the colors that plants could absorb, what color would the plant appear? Question 2: How does the light level (intensity) affect the rate of photosynthesis? Directions: 1. Set the run speed to x5 2. Set the light color to colorless 3. Set the CO2 level to 5 4. Clear the results from the last run 0 2 4 6 Bubble Count Bubble number Light intensity (level) Effectct of Light Intensity on Photosynthsis 8 10 Light Intensity 5. What data points prove that plants need light to photosynthesize? 6. What happens to a plants ability to photosynthesize as the light intensity increases? 7. According to your data, will there ever be a point where light intensity increases but the rate of photosynthesis remains constant? Explain. Question 3: How does CO2 affect the rate of photosynthesis? Directions: 1. Set the run speed to x5 2. Set the light color to colorless 3. Set the light level to 5 4. Clear the results from the last run CO2 Level Effectct of CO2 Level on Photosynthsis Bubble Count 0 4 6 8 10 Bubble number 2 CO2 Level 8. What data points prove that plants need CO2 to photosynthesize? 9. What happens to a plants ability to photosynthesize as the CO2 concentration increases? 10. According to your data, will there ever be a point where carbon dioxide increases but the rate of photosynthesis remains constant? Explain. 11. Why do you think there is an upward limit to the amount of CO2 a plant needs for photosynthesis?