1. Basics of Photosynthesis Simple Definition: Using sunlight to make organic compounds

2. Who cares? Beginning of food chain on land and shallow water Beginning of food chain on land and shallow water Why not in deep water? Why not in deep water? Carbon Dioxide Reduction Carbon Dioxide Reduction Greenhouse gas that leads to global warming! Greenhouse gas that leads to global warming! Oxygen Production Oxygen Production What we breathe! What we breathe! Photosynthesis Photosynthesis Photosynthesis Click the above link and then click “View” – if the site denies you access to the site come let Ms. Bacolas know so I can log in to the site for you. Click the above link and then click “View” – if the site denies you access to the site come let Ms. Bacolas know so I can log in to the site for you.

3. Plants do not eat organic compounds, so they need a process to create them Plants do not eat organic compounds, so they need a process to create them Only about 1% of the sun’s energy is captured by autotrophs to use in photosynthesis. Organisms that can accomplish this include: Only about 1% of the sun’s energy is captured by autotrophs to use in photosynthesis. Organisms that can accomplish this include: Plants Plants Algae Algae Some Bacteria Some Bacteria Occurs in chloroplasts of plants & algae, and in cell membrane of prokaryotes Occurs in chloroplasts of plants & algae, and in cell membrane of prokaryotes

4. Exceptions? Carnivorous Plants – use both photosynthesis and predator-prey tactics for energy Carnivorous Plants – use both photosynthesis and predator-prey tactics for energy Carnivorous Plants Carnivorous Plants Click the above link and then click “View” – if the site denies you access to the site come let Ms. Bacolas or Mrs. Ross know so we can log in to the site for you Click the above link and then click “View” – if the site denies you access to the site come let Ms. Bacolas or Mrs. Ross know so we can log in to the site for you

5. Overall Chemical Reaction: sunlight 6 H 2 O + 6 CO 2 6 O 2 + C 6 H 12 O 6 Water Carbon Oxygen Glucose Water Carbon Oxygen Glucose Dioxide Dioxide What are the reactants? 6 H 2 O + 6 CO 2What are the reactants? 6 H 2 O + 6 CO 2 What are the products? 6 O 2 + C 6 H 12 O 6What are the products? 6 O 2 + C 6 H 12 O 6 What did sunlight provide to the reaction? What do we call this? Activation EnergyWhat did sunlight provide to the reaction? What do we call this? Activation Energy

6. What makes this process possible?? Chloroplasts!

7. Structure of a Chloroplast

8. Stroma – space inside the chloroplast Stroma – space inside the chloroplast where reactions occur where reactions occur where starches are created where starches are created Thylakoids – flattened disk shaped structure Thylakoids – flattened disk shaped structure contains chlorophyll contains chlorophyll site of photosynthesis site of photosynthesis Granum – stack of thylakoids Granum – stack of thylakoids

10. Chloroplasts Are organelles responsible for using light energy to produce carbohydrates from carbon dioxide and waterAre organelles responsible for using light energy to produce carbohydrates from carbon dioxide and water Contain pigments Contain pigments Pigments : light- absorbing molecules Pigments : light- absorbing molecules

11. Before we move on… Why are leaves green? Because of pigments!

12. How do we see? We see because of light hitting our eyes – allowing us to see the image of the thing the light is bouncing off of. The light from the sun is called white light.

13. White Light… really white? Not exactly – sunlight is actually composed of several colors: ROYGBIV (Red Orange Yellow Green Blue Indigo Violet) Which of these colors we SEE has to do with pigments!

14. Remember : pigments are light-absorbing molecules. Remember : pigments are light-absorbing molecules. Whatever colors the pigments do not absorb, gets reflected back to our eyes, and that is the color we see. Whatever colors the pigments do not absorb, gets reflected back to our eyes, and that is the color we see. Plants contain chlorophyll, which absorbs all the wavelengths (colors) of light except for green and yellow – that is why we SEE these colors – because they were reflected/rejected by the chlorophyll. Plants contain chlorophyll, which absorbs all the wavelengths (colors) of light except for green and yellow – that is why we SEE these colors – because they were reflected/rejected by the chlorophyll.

15. Chloroplasts Contain Two Pigments 1. chlorophyll the primary pigment involved in photosynthesis – most light absorbtion the primary pigment involved in photosynthesis – most light absorbtion absorbs mostly reds and blues – reflects greens and yellows absorbs mostly reds and blues – reflects greens and yellows 2. carotenoids pigment that absorbs different wavelengths than chlorophyll – reflects mostly reds, oranges and yellows pigment that absorbs different wavelengths than chlorophyll – reflects mostly reds, oranges and yellows responsible for autumn leaf colors responsible for autumn leaf colors

17. Why do plants grown in the shade have larger leaves than ones grown in full sun? These leaves are both from a White Oak Tree, but they have very different shapes. The one on the left was grown in the shade, and the one on the right was grown in the sun. Why do you think this occurs?

18. Why do leaves change color?? In the fall, there is less hours of daylight and therefore less sunlight. The chlorophyll, no longer having a job to do, begins to break down. As the dominant pigment (chlorophyll) breaks down, we are able to see the carotenoids that were there all along!

19. How do environmental factors affect the rate of Photosynthesis?

20. Affect of Water… Water is needed for the process of photosynthesis. Water is needed for the process of photosynthesis. Plants deprived of water… will not be able to make sufficient food. Plants deprived of water… will not be able to make sufficient food. More importantly… More importantly… Keeps plant cells rigid – central vacuole! Keeps plant cells rigid – central vacuole! Review – how does water get to the top of trees? What do we call this process?

21. Affect of Sunlight… More sunlight = higher rate of photosynthesis More sunlight = higher rate of photosynthesis More photosynthesis/sunlight = more energy More photosynthesis/sunlight = more energy More energy = more bonds can be formed More energy = more bonds can be formed More bonds = more More bonds = more glucose can be made = More food!! = More food!!

22. Affect of CO 2 CO 2 is a reactant in this process CO 2 is a reactant in this process So, more CO 2 = more ingredients = higher rate of photosynthesis So, more CO 2 = more ingredients = higher rate of photosynthesis Some greenhouses actually pump CO 2 into facility to increase growth (photosynthesis) rate Some greenhouses actually pump CO 2 into facility to increase growth (photosynthesis) rate Wake Forest University scientists are currently trying to save a species of Loblolly Pine this way! Wake Forest University scientists are currently trying to save a species of Loblolly Pine this way!

23. Recap of Factors Affecting Photosynthesis Water Water photosynthesis increases as water concentration increases up to a certain point photosynthesis increases as water concentration increases up to a certain point Light Light photosynthesis increases as light intensity increases until all of the pigments are being used photosynthesis increases as light intensity increases until all of the pigments are being used Carbon Dioxide Concentration Carbon Dioxide Concentration increases as concentration increases up to a point increases as concentration increases up to a point Temperature Temperature Photosynthesis occurs at an optimal temperature Photosynthesis occurs at an optimal temperature Why? Why? When it become to hot or cold, transpiration and/or enzyme activity is affected! When it become to hot or cold, transpiration and/or enzyme activity is affected!

24. Stages of Photosynthesis Stage One: Energy is captured from sunlight…Light energy is converted into temporary chemical energy (ATP & NADPH) Stage Two: Chemical energy in ATP is used to create organic compounds