BI 253 Chapter 10

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BI 253 Chapter 10
2012-11-14 12:30:52
BI 253

Photosynthesis 11-14-12
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  1. What are the reactants in photosynthesis?
    • Light
    • Water
    • CO₂
  2. What are the products of a photosynthesis reaction?
    • Carbohydrates
    • O₂
    • More H₂O
  3. Why does water appear on both sides of a photosynthetic reactions?
    B/c water is used as a reactant & released as a product
  4. What are 2 main pathways that occur in chloroplasts?
    • Light reactions
    • Light independent (Dark) reactions
  5. Describe a light reaction? What drives it? Whats produced?
    Reaction driven by light producing ATP & NADPH+H⁺
  6. Why are dark reactions called such?
    B/c they do not use light directly
  7. How do dark reactions produce sugar?
    They use products of light reactions & CO₂ to produce sugar
  8. Light behaves as both a ___ & a ___ & is packaged in packets called ____.
    • Particle & a wave
    • Photons
  9. Receptive molecules that absorb photon wavelengths in a visible range are called ____?
  10. Colors that are absorbed by pigments (can/cannot) be seen where as colors being reflected (can/cannot) seen.
    • Cannot
    • Can
  11. What are the main pigments in plants?
  12. What are the 2 types of chlorophyll in plants?
    • Chlorophyll a
    • Chlorophyll b
  13. What does the structure of chlorophyll look like?
    Ring structure w/hydrocarbon tail
  14. What 2 parameters determine if light can be used for energy?
    • Can they be absorbed by receptive molecules
    • Do they have enough energy to perform chem work required
  15. Shorter wavelength → (higher/lower) energy
  16. Longer wavelength → (higher/lower) energy
  17. What happens to a molecule if a photon is absorbed?
    The molecule is moved fr ground state to excited state
  18. When a molecule moves fr its ground state to an excited state what actually happens?
    e⁻ moves up the antenna sys & further fr nucleus causing it to be more chemically reactive
  19. What does NAD stand for & what does it do?
    • Nicotinimide Adenine Dinucleotide
    • e⁻ carrier for cellular respiration
  20. What does NAD look like when it is carrying e⁻ in cell resp? In photosynthesis?
    • NADH + H⁺
    • NADPH + H⁺
  21. What are the products of non-cyclic reactions?
    • ATP
    • NADPH + H⁺
  22. What are the products of cyclic reactions?
  23. Non-cyclic reactions utilize what photosystems?
    I & II
  24. Cyclic reactions utilize what photosystems?
    I ONLY
  25. What does photosystem I in a non-cyclic reaction do?
    Utilizes light energy to reduce NADP+ → NADPH + H⁺
  26. What is the chlorophyll at the ctr of photosystem I called & why?
    P700 b/c it absorbs light at a wavelength of 700nm
  27. Explain function of photosystem I in non-cyclic reactions.
    • Photon hits P700, e⁻ become excited & avail
    • e⁻ runs thru carriers & produces NADPH + H⁺ fr NADP
    • P700 returns to grd by accepting e⁻ thru ETC fr photo II
  28. Explain photo II in non-cyclic reactions.
    • Photon hits P680, e⁻ becomes excited & avail
    • Excited e⁻ enters ETC driven by Proton Motive Force
    • ADP phosphorylated to make ATP
    • H₂O split into e⁻, p⁺ & O₂ & e⁻ donated back to P680
  29. What does photosystem II do in non-cyclic reaction?
    Uses light to oxidize H₂O to produce e⁻, p⁺ & O₂
  30. What chlorophyll is at ctr of photosystem II?
  31. What process does photosystem I follow?
    • Photon hits P700; e⁻ becomes excited & avail
    • Excited e⁻ → binds to Ferredoxin → ETC
    • ADP phosphorlated → ATP
    • e⁻ fr ETC cycles back to P700
  32. Where do "dark" reactions occur?
    Stroma of chloroplast
  33. An antenna sys plus membrane protein & any assoc accessory pigments are called ____.
  34. Process of e⁻ transport in thylakoid membranes sets up charge separation whose potential energy is captured by chemiosmotic synthesis of ATP is called?
  35. What are 3 pathways of dark reactions?
    • Calvin Cycle
    • C4 photosynthesis
    • Crassulacean Acid Metabolism (CAM)
  36. What are 3 processes in Calvin Cycle?
    • Fixation of CO₂ catalyzed by rubisco producing 3PG
    • Reduction of 3PG → G3P
    • Regeneration of RuBP by ATP
  37. What is formed by the Calvin Cycle?
    Glyceraldehyde-3-phosphate (G3P)
  38. What enzyme catalyzes the Calvin Cycle?
    • Ribulose Bisphosphate Carboxylase/oxygenase
    • AKA Rubisco
  39. Light dependent reactions are driven by ___ & produce what 2 things?
    • Light
    • ATP & NADPH + H⁺
  40. Light independent reactions use light ___ & use what 3 things as reactants to produce ____?
    • Indirectly
    • ATP, NADPH + H⁺ & CO₂
    • Sugar
  41. Light dependent & light independent reactions both occur in the ____.
  42. What is the name given to receptive molecules that absorb photon wavelengths in the visible range?
  43. ____ are main pigments in plants & their structure looks how?
    • Chlorophyll
    • Ring like structure w/hydrocarbon tail
  44. Packets of light that behave as both a particle & wave are called what?
  45. In a non-cyclic reaction both photosystems I & II are utilized to produce what 2 products?
    • ATP
    • NADPH + H⁺
  46. In a cyclic reaction, photosystem I ONLY is utilized to produce what product?
  47. What are 3 processes involved in the Calvin Cycle?
    • CO₂ (catalyzed by rubisco) → 3PG
    • 3PG reduced → Glyceraldehyde-3-phosphate (G3P)
    • RuBP regenerated by ATP
  48. During the Calvin cycle, how is G3P reduced to Glyceraldehyde-3-phosphate?
    3PG phosphorylated w/ATP & reduced w/NADPH
  49. What is the reaction for the Calvin cycle?
    CO₂ + Ribulose Bisphosphate (RuBP) → 3 phosphoglycerate
  50. What is the final product of the Calvin Cycle?
    Glucose & other organic compounds