1. Photosynthesis LN #15 California State Standards for Cell Biology 1f. usable energy is captured from sunlight by chloroplasts and is stored through the synthesis of sugar from carbon dioxide.

2. Overview of Photosynthesis glucose 6 CO 2 + 6 H 2 O C 6 H 12 O 6 + 6 O 2 Light energy CO 2 H2OH2O C 6 H 12 O 6 O2O2 Purpose of photosynthesis is to turn light energy into chemical energy. Chemical energy is stored in glucose.

3. Where does Photosynthesis take place? Photosynthesis takes place in the leaves of plants. Chloroplast is the organelle responsible for carrying out photosynthesis. –In the figure circle the chloroplast.

4. Leaf and Chloroplast Structure

5. Leaf structure –Stomata = tiny pores in the leaf, carbon dioxide enters and oxygen exits. Inside the chloroplast –stroma = thick fluid enclosed in the inner membrane of the chloroplast. The stroma is where glucose is made from carbon dioxide. –thylakoids = disk like sacs within the stroma. Thylakoids are connected in stacks called grana. Chlorophyll molecules are built into the thylakoid membrane. chlorophyll molecules are a pigment that capture light energy.

6. Photosynthesis Occurs In Two Parts

7. Part One: The Light Reactions Light energy is changed into chemical energy. –Oxygen gas is a waste product of this reaction. The light reactions happen in the thylakoid membrane of the chloroplast. Light energy is caught by the chlorophyll and used to make ATP from ADP and phosphate. Light energy is also stored in a molecule called NADPH.

8. Part Two: The Calvin Cycle During the Calvin cycle sugar is made using carbon dioxide and the energy storing molecules (ATP and NADPH) made during the light reactions. Calvin cycle takes place in the stroma of the chloroplast.

9. Summary What is photosynthesis? Where does photosynthesis take place? How many parts does photosynthesis have? What occurs during the light reactions? What occurs during the Calvin cycle?