Presentation on theme: "PHOTOSYNTHESIS Energy is used to make: Proteins Sugars Fats"— Presentation transcript:
1 PHOTOSYNTHESIS Energy is used to make: Proteins Sugars Fats Nucleic acidsAll living things need energy.Energy comes from sun.
2 PHOTOSYNTHESIS Energy is harnessed: Producers (plants) are able to convert this light energy (sunlight) into chemical energy (sugar).
3 PHOTOSYNTHESIS EQUATION: Carbon Water Sugar Oxygen Water Dioxide 6 CO2 Sunlightchlorophyll6 CO2+ 12 H2OC6H12O6+ 6 O2+ 6 H2O
4 CHLOROPLASTSAll cells in leaves have thousands of green organelles called chloroplasts.
5 CHLOROPLASTSStroma: Cytoplasm of chloroplast; contains enzymes for making sugarThylakoid: Flattened sacs; convert light NRG to chemical NRGGrana: Stacks of thylakoids
6 CHLOROPHYLLMolecule that absorbs sunlight energy.Photoreactive core
7 SUNLIGHTWhat do you think would happen if you placed a plant in just green light?Plants appear to be green because chlorophyll does not absorb green wavelengths of light.Just blue light?
8 HOW DOES A CHLOROPLAST WORK? A. Light reactionSunlight is absorbed by chlorophyll in thylakoid.This energy is used to split water.2 H2O O2 + 4 H electrons3. Oxygen is produced.4. Electrons are excited (contain super energy).5. No carbon dioxide is used; no sugar is produced.
9 HOW DOES A CHLOROPLAST WORK? Light reactions harness sunlight to split water, produce oxygen, and excite an electron. Occurs in thylakoids.
10 HOW DOES A CHLOROPLAST WORK? B. Dark Reaction (Calvin Cycle)Enzymes in stroma use the excited electron’s energy to build sugar from CO2 and H+.DOES NOT REQUIRE DARKNESS, BUT CAN HAPPEN IN DARK BUT . . .Only if there are enough excited electrons. Once those run out – photosynthesis is done.
11 Leaf StructureCuticle – waxy layer on top of leaf
12 Leaf StructureEpidermis – outermost layer of cells