1. Heading Page # Photosynthesis Table of Contents

2. Photosynthesis Trapping the Sun’s Energy Chapter 9 Section 2 Pgs. 225-230

3. How do WE harness energy from the sun???

4. What is Photosynthesis? Photosynthesis is the process plants use to trap and make energy from sunlight. The energy is then used to make simple sugars. These simple sugars are then converted to complex carbohydrates These complex carbs are then able to store energy.

5. Where Does Photosynthesis Take Place? Photosynthesis takes place in the chloroplast. Photosynthesis takes place in the chloroplast.

6. Chlorophyll Chloroplasts contain a pigment called chlorophyll. Chlorophyll absorbs most wavelengths of light except for green.

7. The Two Phases of Photosynthesis The Light-Dependent Reactions The Light-Dependent Reactions Requires sunlight Requires sunlight End products End products Oxygen released Oxygen released ATP ATP NADPH NADPH The Light-Independent Reactions The Light-Independent Reactions Does not require sunlight Does not require sunlight End Product End Product NADP + sugar

8. Light Dependent Reactions Light is trapped by chlorophyll in the plant’s leaves The energy from the sunlight is transferred to electrons The electrons move to an electron transport chain (a line of proteins embedded in a membrane)

9. Electron Transport Chain (ETC) Electrons are passed protein to protein As the electrons are passed along this line, some energy is lost.

10. What Happens to the Lost Energy? The energy lost can be used to form ATP from ADP Energy not used is stored in an electron carrier called NADPH. NADPH carries the energy to the light- independent reactions.

11. Restoring Electrons Electrons are lost at the beginning of photosynthesis and must be restored Without restoration chlorophyll can’t absorb light and light dependent reactions stop, causing lack in production of ATP To replace lost electrons, PHOTOLYSIS occurs.

12. Photolysis Splitting of water molecules in the first photosystem Produces ½ molecule of oxygen (released into the air WE breathe) 2 electrons (returned to chlorophyll) 2 hydrogen ions (help provide energy for ATP production)

14. Light-Independent Reactions Does not Require Light Called the Calvin Cycle

15. Calvin Cycle Series of reactions that uses carbon dioxide, ATP, and NADPH to form sugars, which become stored energy It takes 6 rounds of the cycle to form one sugar