1. Obtain some bromothymol blue from your teacher. BTB is a chemical that shows if carbon dioxide is present. 2. Using a straw, gently blow bubbles into the solution until it completely changes color. A. What was the initial color of BTB? o Blue B. What was the color of the solution after we blew bubbles into it? o Greenish - yellow C. What color does BTB change to when carbon dioxide is present? o Greenish Yellow D. What do you think would happen to the color of the solution if the carbon dioxide were used up? o It would go back to blue a. Would the presence of plants in water cause the carbon dioxide to increase, decrease, or stay the same? Explain your answer. o They would cause the carbon dioxide to decrease because of photosynthesis (carbon dioxide is used up) b. When would you expect photosynthesis to happen, in the day or at night? Explain your answer. o More in the day because of the light of the sun Your teacher will set up an experiment using BTB (yellow) and Elodea Plant. Picture to your right shows the experimental set up. We will wait about 50 minutes to record our data a. Why did you need to make sure the BTB solution had completely changed color before starting the experiment? o We need to compare the results to the initial color. b. Write a Hypothesis about what you think will happen to the color of the BTB solution in each of the four containers. (ITB format) Your teacher will set up another experiment using plant seed and BTB (blue) We will check our results in about 45 minutes. Write a prediction about what you think will happen to the color of the solution in each container. The process by which a cell captures energy from the sun and uses it to make food (glucose) THE SUN Raw Materials = Carbon dioxide + Water Products = Sugar (glucose) + Oxygen Equation: 6 CO H 2 O + C 6 H 12 O O 2 Carbon water sugar oxygen Carbon water sugar oxygen dioxide (glucose) dioxide (glucose) Raw MaterialsProducts SUN Chloroplast Respiration is the process by which cells obtain energy from sugar (glucose). During respiration, cells break down simple food molecules like sugar and release the energy they contain. EAT RESPIRATION Plant cells make more energy from the sun than they need They store it as sugars and starches Animals store energy as fats and sugars Raw Materials = Sugar (glucose) + Oxygen Products = Carbon dioxide + Water Equation: C 6 H 12 O O 2 6 CO H 2 O + C 6 H 12 O O 2 6 CO H 2 O + sugar oxygen Carbon water sugar oxygen Carbon water (glucose) dioxide (glucose) dioxide Raw MaterialsProducts ENERG Y Mitochondria Respiration and photosynthesis go hand in hand. What is made during photosynthesis is used during respiration and the products of respiration are used as raw materials for photosynthesis. Photo = light energy Synthesis = putting things together. Occurs in chloroplasts (plants!) carbon dioxide + water + light = oxygen + glucose Occurs in mitochondria (all organisms, plants and animals) Glucose + oxygen = water + carbon dioxide + energy ContainerInitial ColorFinal Color #1 Plant with lightYellowGreen #2 Plant with no lightYellow #3 no plant with lightYellow #4 no plant-no lightYellow ContainerInitial ColorFinal Color #1 with seedsBlue #2 No seedsBlue Photosynthesis Experiment - A Cellular Respiration Experiment - B 1. Experiment A: In which container(s) did photosynthesis occur? Use your data and knowledge of photosynthesis to explain your answer. 2. Did the results from Experiment A support your hypothesis? 3. Experiment B: In which container did cellular respiration occur? Use your data and knowledge of cellular respiration to explain your answer. 4. Did the results from Experiment B support your hypothesis? 5. Why was light a variable in Experiment A but not a variable in Experiment B? 6. Summarize what you learned during this investigation. (At least 3 sentences)