Photosynthesis 8-2/8-3

1.Photosynthesis stores energy from light in the bonds of carbohydrates. 2. Water provides electrons, releasing oxygen into the atmosphere. 3.Carbon dioxide is the carbon source for building carbohydrates.

4. Photosystems consist of antenna complexes and their associated electron transport molecules. 5. Eukaryotic photosystems are located on the thylakoid membrane inside chloroplasts. 6. Chloroplasts are abundant in the mesophyll tissue of leaves.

7. Electrons enter Photosystem II from water molecules. 8. As electrons move along the electron transport system toward Photosystem I their energy is used to make ATP. 9. These electrons then enter Photosystem I and are lost to an electron acceptor which aids the formation of NADPH. 10. ATP and NADPH are necessary for the light- independent reactions.

Light Independent Reactions 11. The Calvin cycle occurs in the stroma of the chloroplast. 12. ATP and NADPH from the light-dependent reactions fuel the Calvin cycle which uses carbon dioxide to build carbohydrates. 13. ADP and NADP + return to the thylakoid to be used again.

Why is Photosynthesis Important? 14. Life is powered by sunlight. 15. The energy used by most living cells comes ultimately from the sun. 16. Plants, algae, and some bacteria use energy from sunlight, particularly blue and red wavelengths, to build molecules which later can be split through cellular respiration to retrieve some of that energy.

Roses are red, violets are blue. If the green plants go, then so do you!” 17. Storing energy in molecules and then oxidizing those molecules to retrieve the stored energy maintains all life on Earth. 18. Plants are often called ‘producers’ because they produce energy-storing molecules used by almost all other organisms on Earth. 19. By eating plants, herbivores ‘steal’ these energy- storing molecules to maintain their own life processes. 20. By eating animals, carnivores ‘plunder’ the molecules that store the energy originally captured by plants. 21. By feeding on dead tissue, decomposers exploit whatever molecules remain in the dead the plants, herbivores, and carnivores. 22. Ultimately, the process of photosynthesis is the most important chemical reaction on Earth. “