2.  Name some common producers › Plants, algae, some protists, cyanobacteria  Define photoautotroph › An organism that uses light energy to produce food  Define chemoautotroph › An organism that uses chemical energy to produce food

3. Fig. 10-2 (a) Plants (c) Unicellular protist 10 µm 1.5 µm 40 µm (d) Cyanobacteria (e) Purple sulfur bacteria (b) Multicellular alga

4.  State the organelle of photosynthesis › Chloroplast  Where are chloroplasts concentrated in plants? › The green tissue on the interior of the leaf › Mesolphyll

5. Fig. 10-3a 5 µm Mesophyll cell Stomata CO 2 O2O2 Chloroplast Mesophyll Vein Leaf cross section

6.  Explain how gases are exchanged between the plant and the environment. › Stoma are openings in the epidermis of leaves › Guard cells surround the stoma and they regulate the opening & closing of the stoma › When open, CO 2 can enter while O 2 and H 2 O can exit

7. Fig. 10-3b 1 µm Thylakoid Space (lumen) Chloroplast Granum Intermembrane space Inner membrane Outer membrane Stroma Thylakoid Structure of the chloroplast Thylakoid is site of light reactions Stroma is site of Calvin Cycle

8.  1950’s – scientists used heavy isotope of oxygen ( 18 O) to follow oxygen through photosynthesis.  Tagged oxygen of CO 2 and found no tagged O 2 given off  Tagged O 2 of H 2 O and found tagged O 2 given off

9. Reactants: Fig. 10-4 6 CO 2 Products: 12 H 2 O 6 O 2 6 H 2 O C 6 H 12 O 6

10.  Equation › 6CO 2 + 6H 2 O  Light  C 6 H 12 O 6 + 6O 2  Redox reaction of photosynthesis › Oxidized:  H 2 O to O 2 › Reduced:  CO 2 to C 6 H 12 O 6

11.  Photosynthesis consists of the light reactions (photo – absorbs light energy) and the Calvin cycle (synthesis – makes sugar)

12. Light Reactions Calvin Cycle  Takes place in the thylakoids  Split H 2 O  Release O 2  Reduce NADP+ to NADPH  Produce ATP via photophosphorylation  Takes place in the stroma  Forms sugar using › CO 2 from atmosphere › ATP and NADPH from light reactions  Starts with carbon fixation

13. Light Fig. 10-5-4 H2OH2O Chloroplast Light Reactions NADP + P ADP i + ATP NADPH O2O2 Calvin Cycle CO 2 [CH 2 O] (sugar)