Elodea and bromothymol blue lab results. Lesson Plan on Photosynthesis 2022-10-22
Elodea and bromothymol blue lab results
Elodea is a type of aquatic plant that is often used in lab settings, particularly in biology classes, to demonstrate photosynthesis and cellular respiration. Bromothymol blue (BTB) is a chemical indicator that is often used in conjunction with elodea to demonstrate these processes. When BTB is added to a solution containing elodea, it can change color depending on the concentration of carbon dioxide (CO2) and hydrogen ions (H+) present in the solution. This allows students to observe and measure the effects of photosynthesis and cellular respiration on the concentration of these substances.
During photosynthesis, elodea absorbs CO2 from the air and uses it, along with light energy, to synthesize glucose. The glucose is then used by the plant as an energy source during cellular respiration. During cellular respiration, elodea breaks down the glucose to release energy, which it uses to perform various functions. This process also produces CO2 and H+ as byproducts.
When BTB is added to a solution containing elodea, it changes color based on the concentration of CO2 and H+ present in the solution. If the concentration of CO2 is high and the concentration of H+ is low, the BTB will turn yellow. If the concentration of CO2 is low and the concentration of H+ is high, the BTB will turn blue. If the concentrations of CO2 and H+ are balanced, the BTB will remain green.
In a lab setting, students can observe the effects of photosynthesis and cellular respiration on the concentration of CO2 and H+ in a solution containing elodea and BTB. By shining a light on the elodea or adding a source of glucose, students can stimulate photosynthesis and observe the resulting increase in the concentration of CO2 and decrease in the concentration of H+. Similarly, by depriving the elodea of light or removing the source of glucose, students can stimulate cellular respiration and observe the resulting decrease in the concentration of CO2 and increase in the concentration of H+.
Overall, the elodea and BTB lab is a useful tool for demonstrating the processes of photosynthesis and cellular respiration and for allowing students to observe and measure the effects of these processes on the concentration of CO2 and H+ in a solution.
Lesson Plan on Photosynthesis
How do you think plants get energy?. Students can draw from already existing sources e. Demo Station 2: Growth factors of a plant: 1 Prepare 3 different pots of plants that are the same size relevantly same size. Place a piece of elodea in each test tube or glass. On the basis of the rate of bubble production observed, students should determine over what period of time e. How do you think plants get energy? This will be done as a group project.
The sugar molecules come from the soil. Demo Station 1: Photosynthesis of an aquatic plant: 1 Place a submersed aquatic plant e. If there is no answer from students, teachers can also ask students to write their answer on a piece of paper and put them in a box. The inside of a plant cell is completely solid. Teacher may also post summary data on a class summary chart on the board.
The inside of a plant cell is completely filled with air. Names the inputs and outputs involved in respiration. Describe the phenomena of transpiration, photosynthesis and cellular respiration 2. Ask students to compare their results with their hypothesis. Yellow pH less than 6. Note: If you do not have access to oxygen gas, just seal the terrarium.
Note: Because the control tubes will collect bubbles, it is important for students to count only the number of bubbles that come from the plant or plant surrogate that rise to the surface. Note : If multiple lamps and test tube racks are available, this experiment can be replicated by splitting the class into groups of three or four and carrying out the same measurements at each station. Note : If you do not have enough solution, you may dilute it with a little water. Note: The following Activity 2 and 3 are optional. Illustrate the relationship between carbon dioxide and photosynthesis 4. Facilitate the discussion as teacher walk around the classroom.
What evidence do you have from the activities we have done in class? Science Activities: Classroom Projects and Curriculum Ideas, 45 1 , 13—22. Teachers should attempt to have all plant clippings be as similar as possible i. The plant makes its food from minerals and water. If there is no answer from students, teachers can also ask students to write their answer on a piece of paper and put them in a box. Energy from photosynthesis is transferred to the consumer. The reason for this colour change is that the carbon dioxide released during photosynthesis reacts with the water to form carbonic acid.
As a group, students have another opportunity to discuss about their understandings on photosynthesis with their peers in informal ways. Students are also invited to record their observation on the worksheet given. Note: You may re-voice their explanations and write their response on a board. Note: Teacher may go over the questions with students and have them present their answers and explanations. Where does the food that a plant needs come from? Note : Teacher can have a class discussion to share their data. Before starting the lesson, does there anyone know where plants get their energy from? Step 4 of the Lesson: Developing Evidence-Based Explanations The goal of this step is to help students in changing their preconceptions through developing complex evidence-based explanations after their investigations in light of the data they gathered in the above activities. Activity Option 2 — Light! Afterward, teachers can choose one of the option activities i.
Humans eat both vegetables and meat which are both products of photosynthesis. Meat is a product of animals eating producers or other consumers. Note : As they add Carbon dioxide into the tube, the bromothymol blue solution will change its colour to yellow acidic. If multiple plant species are available, add an additional test tube for each additional species and place 5-cm cuttings of those species into their own test tubes. Teacher will then write some response on a board or a chart paper for discussion.
Have students to label three test tubes e. Why do you think so? Activity Option 3 — Role of Carbon Dioxide and Light 1 Set up the lamps at least several feet apart and away from windows. Ask students to answer the questions on the worksheet Appendix B. Step 3: Collecting and Making Sense of Data: In this step, teacher will conduct the Activity 1 — An Oxygen Factory. The test tubes with these plant surrogates act as controls. The goal of this activity is to illustrate the causal relationship between light and photosynthesis i. After students fill out most part of the worksheet, ask them to discuss in a small group 3-4 students.