1 / 19

Intro to Photosynthesis & the Light Reactions

Intro to Photosynthesis & the Light Reactions. AP Biology Chapter 10.1-10.2. Learning Target 1 (10.1). I can describe how photosynthesis converts light energy into the chemical energy of food. Quick Review: Obtaining Energy. Life on Earth is solar powered Directly: autotrophs

yan
Télécharger la présentation

Intro to Photosynthesis & the Light Reactions

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. Intro to Photosynthesis & the Light Reactions AP Biology Chapter 10.1-10.2

  2. Learning Target 1 (10.1) I can describe how photosynthesis converts light energy into the chemical energy of food.

  3. Quick Review: Obtaining Energy • Life on Earth is solar powered • Directly: autotrophs • Indirectly: heterotrophs

  4. Chloroplasts • Photosynthetic prokaryotes lack chloroplasts • photosynthetic membranes = enfolded regions of the plasma membrane

  5. Photosynthesis • Equation: • Part I: Light Dependent Reactions (thylakoid membrane) • Part II: Light Independent Reactions (stroma) oxidation reduction

  6. Plant Structure • Roots • Stems • Leaves • Epidermis • Waxy covering to prevent excess water loss • Mesophyll • Contains photosynthetic cells • Stoma • Openings for gas exchange • Guard cells control

  7. Learning Target 2 (10.2) I can explain how the light reactions work to convert solar energy to the chemical energy of ATP and NADPH.

  8. Light • Form of electromagnetic radiation • Energy is inversely related to its wavelength • Shorter wavelengths pack more energy • Visible light is 380-750 nm

  9. Plants are green because… • Chlorophyll absorbs two wavelengths of light: • Blue (420 nm) • Red (660 nm)

  10. Light Reactions Part of photosynthesis that prepares to make glucose

  11. Photosystems • Photosynthetic units within chloroplast grana

  12. Light Dependent Reactions – Non-cyclic (Linear) Electron Flow • Produces ATP and NADPH using Photosystems I & II

  13. Sunlight strikes the Photosystem II complex and excites electrons, eventually passing it to the primary electron acceptor • Excited electron splits H2O into H+ ions and O2 gas

  14. Electrons flow through a series of membrane proteins, pumping H+ ions into the thylakoid space • Collection of H+ ions pass back to stroma through ATP synthase in thylakoid membrane • ADP is converted into ATP

  15. Sluggish electrons receive another photon of light in PSI • Excited electrons are passed to NADP reducing it into NADPH

  16. Light Reaction Summary • Reactants: • H2O • Light • NADP+ • ADP + Pi • Products: • O2 • NADPH • ATP

  17. Light Dependent Reactions – Cyclic Electron Flow • Produces ATP only using photosystem I • Evolutionary “leftover” of photosynthetic bacteria?

  18. Light Dependent Reaction Animation • http://highered.mcgraw-hill.com/olc/dl/120072/bio13.swf

More Related