Understanding Photosynthesis: From Light to Energy

1. PHOTOSYNTHESIS

2. The process of converting solar energy to chemical energy (glucose) via 2 steps: 1. ______________ 2. ____________ aka _____________ Involves the use of: • __________ • Chlorophyll a, Chlorophyll b, Carotenoids • _______________________ • ATP, NADH, NADPH & FADH2 Overview

3. All organisms need _________ • Energy obtained/used by organisms either comes ___________________________ The Light Reactions

4. Refer to Fig 6-1 bottom of pg 113 • Organisms are classified by how they get energy • ____________ – organisms who capture sunlight and convert it to organic compounds • Make their own food • Get energy ___________ from the source (sun) • _____________ – organisms who get their energy from food • Do not make their own food • Get energy _____________ from autotrophs or other heterotrophs Obtaining Energy

5. Refer to figure 6-2: Autotrophs and Heterotrophs are connected • Autotrophs _________________________ • Using carbon dioxide, water and light energy • Make organic compounds (glucose) and oxygen • Heterotrophs __________________________ • Using the products of photosynthesis – Organic compounds and oxygen • Break the bonds of organic compounds to get energy and release carbon dioxide and water Overview of photosynthesis

6. 2 reactions of Photosynthesis • Light Reactions • Input: _______________ • Output: _________________________ • NADPH and ATP are E storing molecule • Calvin Cycle aka Dark Reactions • Input: ___________________________ • Output: __________________________ Overall Reaction for Photosynthesis: ______________________________________ Overview of Photosynthesis cont’d

7. Light Reactions • Named this because it requires the absorption of light • Light is absorbed by organelles in plant cells called chloroplasts • Chloroplasts include: • __________________ • __________________ • __________________ • __________________ • _______________ Capturing light energy

9. Refer to Figure 6-4 on pg 115 • White light that we see from the sun is actually broken down into various colors • Called the ____________________ • The different colors of light are measured in wavelengths • Each color has a ________________________ • When light hits an object that light can be: • __________________________, or _______________ • Compounds that _____________ are called ___________ • Pigments vary in the wavelengths they absorb from the visible spectrum. Light and Pigments

10. Refer to Fig 6-5 pg 115 • Pigments in plant cells are found in the thylakoid of chloroplasts • Include: Chlorophyll a, Chlorophyll b, Carotenoids • Chlorophyll a ___________________ • Chlorophyll b and Carotenoids  _____________________ • By looking at the figure what can you say about the light that is absorbed by these pigments? Chloroplast Pigments

11. Converting light energy chemical energy Overall Reaction for Photosynthesis: _____________________________________

12. Light Reactions • Take place in _________________ • Both the membrane itself and the space inside • Refer to fig 6-6 pg 116 • Steps of Light Reactions • _______________ • _________________________ (of PSII) • _______________ • _________________________ (of PSI) Converting light energy chemical energy

13. Steps of Light Reaction 1. Photosystem II • Location: ___________________ • Input: ___________________ • Output: ____________let out to atmosphere and _______________ Converting light energy chemical energy

14. 2. Electron Transport Chain (of PSII) - Location: __________________ - Input: ________________________ - Output: _______ (energy molecule) made from ___________________ - using a concentration gradient (of protons) that turns on ATP synthase in membrane that make ATP - ____________ = an exzyme that makes ATP by adding a Phosphate to ADP Converting light energy chemical energy

15. 3. Photosystem I - Location: _______________________ - Input: ____________ - Output: ____________________ 4. Electron Trasnport Chain (of PSI) - Location: ______________________ - Input: _____________________ - Output: _______________ (energy molecule) Converting light energy chemical energy

17. From Light Reactions we have gotten: - _________ – let out into the atmosphere - ________ - ___________ Heading into the Calvin Cycle - Moving out of thylakoid into the _______ - Using __________________ as energy to fuel this phase - Also using _________from atmosphere

18. Converting light energy chemical energy Overall Reaction for Photosynthesis: ________________________________

20. No light necessary • Uses the _____________ from the light reactions as well as_____ from the atm • Enters through _______ (pores in the leaves) • _______________are formed • Importance: These sugars are used by autotrophs and hetertrophs for energy Calvin cycle

21. Steps of Calvin Cycle (3)

22. _________ go into the cycle one at a time to react with ________(ribulose biphosphate) Enzyme ___________ helps Result: _________ is formed Step 1: Carbon fixation

23. Step 2: Converting PGAG3P • Energy from_____ __________ used to change PGA into _______ • Energy molecules are now depleted • NADPHNADP+ • ATPADP • Result: G3P is made • Two G3P molecules can be combined to form _________

24. Step 3: Restocking RuBP • Using ATP the rest of the ____molecules are turned back into ______ • Result: ___________

26. Input/output of Calvin Cycle

27. _______________________ come and go through small pores in plants called stomata ___________________ loose water/CO2 and O2 at a faster rate and therefore have different ways of making _____________ Alternative pathways

28. 1. __________________ • As light increases the rate if photosynthesis increases • Note: At a certain level of light intensity there is plateau • 2. _______________________ • As CO2 increases so does the rate of photosynthesis • Note: At a certain point there is plateau • 3. _________________ • As temp raises the rate of photosynthesis also raises • At certain temps stomata will close and the enzymes can denature resulting in the rate to decrease Factors that Effect Photosynthesis

29. The End!