Understanding Photosynthesis: The Power of Sunlight in Ecosystems

1. What do all living things need?

2. Energy! All living things need a constant flow of energy

3. The Food Pyramid Top Consumers Primary Consumer Producer Top Consumer Secondary Consumer Plant Carnivore Herbivore Secondary Consumers Carnivores Primary Consumers Herbivores Decomposers Fungus & Bacteria Producers Plants

4. From where do the producers get their energy? From the SUN!!!

5. By what process do the producers capture solar energy & convert it into a usable form for all living things?

6. When we are done with this chapter, you will be able to… • Explain why Photosynthesis is necessary • Tell where photosynthesis takes place • What is the formula for photosynthesis • Explain how photosynthesis occurs • Reactants & products of the Light reaction • Reactants & products of the Calvin Cycle

7. Chapter 4:Photosynthesis Let’s get into this

8. Energy produced by the producers (with the energy from the sun) is transferred from one organism to the next. Sun Producers Primary Secondary Consumers Consumers

9. Photosynthesis • Process by which green plants or organism with chlorophyll, convert light energy into the chemical energy in the bonds of carbohydrates

10. Autotrophic – • Can transfer energy to produce food – can make their own food • Plants, some bacteria & some protists • Heterotrophic – • Must obtain energy from preformed food – must eat food • Fungus, all animals, some bacteria & protists

11. What is needed for autotrophs to photosynthesize? • Carbon dioxide (atmospheric) • Water (in the soil or air) • Sunlight (or artificial light source) • Chlorophyll (present in leaves and sometimes stems)

12. General formula for Photosynthesis

14. Where does Photosynthesis take place in a leaf? • Chloroplasts are small oval structures containing the green pigment chlorophyll on the leaves of plants

15. What does a chloroplast look like? Chloroplastsare oval structures consisting of stacked grana (photosynthetic membranes) • and a liquid called stroma. • Chlorophyll is found in the stacked grana Grana

16. Photosynthesis occurs in 2 major steps Chloroplast Light Reaction occurs in the... Grana (contains chlorophyll) Calvin Cycle occurs in the... Stroma

17. Step 1 – The Light Reaction • Occurs only in the presence of light. • Occurs in the grana (stacks) of the chloroplasts • Light is used to split water molecules into hydrogen and oxygen and to move electrons through the membranes of the grana to produce ATP

18. Light Dependent Reaction Light Independent Reaction Membrane of the Grana Occurs in Stroma Glucose

19. Step 2. Calvin Cycle (Light independent reaction) • can occur in light or darkness. Follows light reaction • Occurs in the stromaof the chloroplasts • CO2 will get “fixed up” with the ATP energy from the light reaction (and hydrogens also from the Light Reaction) to produce Glucose

20. Membrane of the Grana Occurs in Stroma Glucose

22. The Steps in Photosynthesis THE LIGHT REACTION •  1) The light energy strikes the leaf, passes into the leaf and hits a chloroplast inside an individual cell. •  2) The light energy, upon entering the chloroplasts, is captured by the chlorophyll inside a grana. •  3) Inside the grana some of the energy is used to split water into hydrogen and oxygen. Produces ATP molecules •  4) The oxygen is released into the air.

23. The Calvin Cycle (Light Independent Reaction) 5) The hydrogen is taken to the stroma along with theATP energy from the Light Reaction.  6) Carbon dioxide enters the leaf and passes into the chloroplast.  7) In the stroma, the remaining light energy is used to combine hydrogen and carbon dioxide to make carbohydrates. This occurs during the Calvin Cycle  8) The energy-­rich carbohydrates (Glucose) are carried to the plant's cells.

24. H

25. Look at the diagram of photosynthesis from the previous slide. What are the names of the two reactions that are occurring in the chloroplasts Describe what reactants are going in and what products are going out. H

26. Summary

27. Great Summary of Photosynthesis & Respiraton • Animation • Another good one

28. H2O ATP Yes Water Oxygen No Sunlight Hydrogen No No Nothing CO2 and Hydrogens (from the light reaction) Glucose The Glucose will be used for energy for the cell Nicholl

29. PHOTOSYNTHESIS REVIEW • What is the definition of Photosynthesis? • What are the reactants for Photosynthesis? • 3. What are the products? • 4. What happens during the light reaction of Photosynthesis? • 5. What is made during the Calvin Cycle? • 6. In what structure is chlorophyll found within a chloroplast?

30. PHOTOSYNTHESIS REVIEW • What occurs in the stroma of a chloroplast? • Does the light reaction have to occur in the light? • Does the light independent reaction have to occur in the dark? • 10. Why is glucose so valuable to all living things? • 11. Why are plants known as autotrophs (or “producers”)?