1 / 22

Photosynthesis Chapter 10

Photosynthesis Chapter 10. Photosynthesis. P rocess that converts solar energy into chemical energy Directly or indirectly, photosynthesis food for almost the entire living world. Photosynthesis.

gage
Download Presentation

Photosynthesis Chapter 10

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. PhotosynthesisChapter 10

  2. Photosynthesis • Process that converts solar energy into chemical energy • Directly or indirectly, photosynthesis food for almost the entire living world

  3. Photosynthesis Photosynthesis is a complex series of reactions that can be summarized as the following equation: 6 CO2 + 12 H2O + Light energy  C6H12O6 + 6 O2 + 6 H2O

  4. Autotrophs= produce own food • Autotrophs are the producers of the biosphere, producing organic molecules from CO2 and other inorganic molecules • Almost all plants are photoautotrophs • Uses the energy of sunlight to make organic molecules

  5. Photosynthesis • Initial Source of Energy for Most Systems • Primary Producers= source of organic molecules for most other organisms • Terrestrial Systems= Plants • Aquatic Systems= Phytoplankton • Consumers= heterotrophs= consume organic material from other organisms • Cellular Respiration Primary Producers Consumers Decomposers

  6. Photosynthesis • Plants use ~50% of sugars produced for cellular respiration to fuel own cellular processes • Rest of sugar is used as building blocks for other organic molecules • Ultimately, consumed by heterotrophs and used for cellular respiration

  7. Figure 10.2 (b) Multicellularalga (c) Unicellularprotists (e) Purple sulfurbacteria Primary Producers: plants, algae, protists, and some prokaryotes (a) Plants These organisms feed not only themselves but also most of the living world. (d) Cyanobacteria 40 m 10 m 1 m

  8. Consumers • Heterotrophs are the consumers of the biosphere • Heterotrophs= obtain organic material from other organisms • Almost all heterotrophs, including humans, depend on photoautotrophs for food and O2

  9. Humans rely on primary producers for other types of fuel • The Earth’s supply of fossil fuels was formed from the remains of organisms that died hundreds of millions of years ago • In a sense, fossil fuels represent stores of solar energy from the distant past • Biofuels

  10. Chloroplasts • Energy-producing organelle in plants • Converts solar energy into chemical energy • Contains green pigment known as chlorophyll • Light absorbing pigment • Gives leaves the green color • All green parts of plant have chloroplasts • Chloroplasts are found mainly in cells of the mesophyll, the interior tissue of the leaf • Cells can have 30-40 chloroplasts

  11. Figure 10.4a Leaf cross section Chloroplasts Vein Mesophyll Stomata CO2 O2 Chloroplast Mesophyllcell 20 m

  12. Figure 10.4b Chloroplast Outermembrane Thylakoid Intermembranespace Granum Stroma Thylakoidspace Innermembrane 1 m

  13. Photosynthesis • Photosynthesis is a complex series of reactions that can be summarized as the following equation: 6 CO2 + 12 H2O + Light energy  C6H12O6 + 6 O2 + 6 H2O • Chloroplasts split H2O into hydrogen and oxygen, incorporating the electrons of hydrogen into sugar molecules and releasing oxygen as a by-product

  14. Figure 10.5 Photosynthesis Reactants: 6 CO2 12 H2O 6 H2O Products: C6H12O6 6 O2

  15. Photosynthesis • Endergonic reaction • Sunlight • Energy stored in bonds of glucose • Redox Reaction • Photosynthesis reverses the direction of electron flow compared to respiration • Oxidation= loss of electrons • Water is oxidized • Reduction= gain of electrons • Carbon dioxide is reduced

  16. Figure 10.UN01 Photosynthesis becomes reduced C6 H12 O6 6 O2 Energy  6 CO2  6 H2O becomes oxidized

  17. Photosynthesis occurs in 2 stages • Light Reactions (“photo) • Occurs in thylakoids • Split H2O • Release O2 • Reduce NADP+ to NADPH • Generate ATP from ADP by photophosphorylation

  18. Figure 10.6-1 H2O Light NADP ADP +P i LightReactions Chloroplast

  19. Figure 10.6-2 H2O Light NADP ADP +P i LightReactions ATP NADPH Chloroplast O2

  20. Photosynthesis occurs in 2 stages • Dark Reactions: Calvin Cycle (“synthesis”) • Occurs in the stroma • Uses ATP and NADPH from light reaction to reduce CO2 and produce sugars • Begins with carbon fixation, incorporating CO2 into organic molecules

  21. Figure 10.6-3 CO2 H2O Light NADP ADP +P i CalvinCycle LightReactions ATP NADPH Chloroplast O2

  22. Figure 10.6-4 CO2 H2O Light NADP ADP +P i CalvinCycle LightReactions ATP NADPH Chloroplast [CH2O](sugar) O2

More Related