1. Introduction to Photosynthesis Biology 11 S.Dosman

3. Chlorophyll the light absorbing green-colored pigment that begins the process of photosynthesis.

4. Guard cell photosynthetic epidermal cells of a leaf or stem that form and regulate the size of an opening called a stoma.

5. Stomata openings on the surface of a leaf that allow for the exchange of gases between air spaces in the leaf interior and the atmosphere

6. Transpiration the loss of water vapor from plant tissues, primarily through stomata.

7. Stroma the protein-rich semi-liquid material in the interior of a chloroplast.

8. Thylakoids a system of interconnected flattened membrane sacs forming a separate compartment within the stroma of a chloroplast.

9. Grana a stack of Thylakoids.

10. Thylakoid membrane the photosynthetic membrane within a chloroplast that contains light gathering pigment molecules and electron transport chains.

11. Light reactions the first set of reactions of photosynthesis in which light energy excites electrons in chlorophyll molecules, powers chemiosmotic ATP synthesis, and results in the reduction of NADP+ to NADPH.

12. Carbon fixation the process of incorporating CO 2 into carbohydrate molecules.

13. Electromagnetic Spectrum photons separated according to wavelength.

14. Calvin Cycle a cyclic set of reactions occurring in the stroma of chloroplasts that fixes the carbon in carbon dioxide into carbohydrate molecules and recycles enzymes.

15. Photons packets of EM radiation (also known as quanta)

16. Action Spectrum a graph illustrating the effectiveness with which different wavelengths of light promote photosynthesis.

17. Absorption Spectrum a graph illustrating the wavelengths of light absorbed by a pigment.

18. Excitation the absorption of energy by an atom’s electron.

19. Photosystem I a Photosystem embedded in the Thylakoid membrane containing chlorophyll P700.

20. Photosystem II a Photosystem embedded in the Thylakoid membrane containing chlorophyll P680.

21. Photophosphorylation the light-dependent formation of ATP by chemiosmosis in photosynthesis.

22. 1. What types of organisms carry out photosynthesis? Photosynthesis is carried out by organisms that contain chloroplasts such as plants, algae, some protists and cyanobacteria.

23. 2. Identify the chemical equation that summarizes the overall process of photosynthesis. 6CO 2 + 6 H 2 O + light energy →C 6 H 12 O 6 + 6O 2

24. 3. What does a plant need in order to perform photosynthesis? Plants need chlorophyll in their chloroplasts along with carbon dioxide, water and light from their environment in order to perform photosynthesis.

25. 4. How does carbon dioxide and oxygen enter and exit the leaves of plants? The leaves of plants contain guard cells that open and close stoma (microscopic openings) to allow carbon dioxide into plants and oxygen out.

26. 5. What is the role of the guard cells and stoma? The guard cells change shape by moving water in and out via osmosis and this allows them to open and close the stoma. They will open and close in response to environmental conditions such as temperature. In general, the stoma are open during the day and close at night to prevent water loss.

27. 6. What three steps summarize the reactions of photosynthesis? Capturing light energy Using captured light energy to make ATP and reduced NADP+ (NADPH) Using the free energy of ATP and the reducing power of NADPH to synthesize organic compounds such as glucose from CO2

28. 7. Where do the two stages of the light dependent reactions occur? The first two stages of photosynthesis are part of the light dependent reactions and they occur on the thylakoid membranes of the chloroplast. They require light energy that is absorbed by the chlorophyll molecules in the membrane.

29. 8. Where does carbon fixation take place? Carbon fixation is the third stage of photosynthesis and it occurs in the stroma of the chloroplast.

30. 9. Identify the three parts of the light dependent reactions. The three parts of the light independent reaction are photoexcitation, electron transport and chemiosmosis.

31. 10. What are the end products of the light reaction that are needed for the Calvin cycle? The light reactions transfer light energy into ATP and NADPH which are the products that are needed for the Calvin cycle.

32. 11. What are the three phases of the Calvin cycle? The three phases of the Calvin cycle are carbon fixation, reduction reactions and RuBP regeneration.

33. 12. G3P is the final product of the Calvin cycle. What organic molecule can be synthesized from G3P? Glucose is the molecule that is synthesized from G3P.