Energy: Photosynthesis: Light reaction

Power standard 5
B2.1A
B2.4f
B2.5C
B2.5D
B3.1A
B3.1B
B3.1C
B3.1e
B3.1f

Goal: Provide the students with a multi-sensory experience to explain the light reaction, which is the first reaction within the overall reaction of photosynthesis.

Objective:
1. Identify ATP as the main source of cellular enegy and that energy is stored in the phosphate bonds.
2. Write the photosynthesis equation and identify where the inputs and outputs of the equation come from.
3. Describe the 2 main parts of a chloroplast and their roles in photosynthesis.
4. Identify each step of the light reaction and explain how they work together.
5. Relate knowledge from previous units (cell transport, cell organelles, macromolecules) to photosynthesis.

Room organization: Place the desks in a U shape (represents the boundaries of the chloroplast), Put 3 varying size plyo boxes in the center of the U (represents the electron transport chain), print off the light reaction ppt slides an place them in the correct location based off of the photosynthesis animation.

Materials: Photosynthesis notes, light reaction diagram, photosynthesis animation, photosynthesis concept map, light reaction ppt slides

Starter: Organize their notebooks so they can turn them in after class. As the students are doing this pass out the light reaction drawing, photosynthesis notes, and the photosynthesis concept map.


Lesson:


Begin the lesson by discussing the first 6 slides of the ppt. Discuss the different types of energy and the type of energy we are going to focus on (chemical energy in the form of ATP). Then discuss photosynthesis in general. Break down the word photo...light and synthesis...create. Make the connection that there is two parts to the word just like there are two reactions, the light dependent and the Calvin Cycle. Discuss the equation for photosynthesis. Inform them that they need to know the equation. Then talk about the organelle that photosynthesis takes place int (chloroplast). Discuss the two main parts and which reaction takes place where (stroma: Calvin cycle and thylakoid (membrane): light reaction). Orient the class with the room set up so they know what they are looking at.


Make sure the students have their light reaction diagrams in front of them. Show them the photosynthesis animation (light reaction) all the way through and then go back and discuss each step as it is happening. The students are to draw each step as I am explaining it. 


After we go through the animation, then I will play the role of an electron in a water molecule and walk through the light reaction. As I am walking through the reaction I will ask individuals questions to get me through the reaction. When I am done, I will call on a student volunteer to walk through the light reaction. The student will play the role of an electron in a water molecule. I will call on individuals and ask them questions that will lead the student volunteer to the next step. After the class has helped the student get through the light reaction, I will have the student go through it by his/herself and explain each step. 


When we are done watching, talking, and walking through the light reaction have the students complete the first part of the photosynthesis concept map. They can use their notes, diagrams, and book to help them.