PHOTOSYNTHESIS

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PHOTOSYNTHESIS

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Chloroplast
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• http//www.stolaf.edu/people/giannini/flashanimat/
  metabolism/photosynthesis.swf

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Chemiosmosis Production of ATP

• Requires a phospholipid bi-layer, a proton pump,
  protons and ATP synthase.
• Chemical Energy is used to pump protons through a
  proton pump (intrinsic protein).  This creates a
  high concentration of protons (H) inside the
  thylakoid disk. ATPase has a channel that allows
  for the facilitated diffusion of protons back in
  through the membrane.  This activates ATPase,
  which in turn catalyzes the formation of ATP.

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• Creates a high concentration of protons (H)
  inside the thylakoid disk.
• ATPsynthase has a channel that allows for the
  facilitated diffusion of protons back in through
  the membrane. 
• This activates ATPsynthase, which in turn
  catalyzes the formation of ATP.

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Photosynthesis takes place in the leaves.

• The cells of the mesophyll layer of the leaf are
  packed with chloroplasts.
• Chloroplast filled with thylakoids stacked into
  grana. (chlorophyll)
• The grana are surrounded by the liquid stroma.

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Photosynthesis Summary

1. Light is captured from sunlight
2. Light energy is converted to ATP and NADPH.
3. Calvin cycle to form sugar.

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1. Light Energy is Captured

• Photon strike (radiant energy on leaf)
• A photon is a tiny packet of radiant energy.
• Chlorophyll a and b (green), located in the
  thylakoid membrane absorb light. Chlorophyll
  loses electrons.
• Carotinoids (yellow and orange) absorb light.
• These pigments are arranged in photo-systems I
  and II and boost electrons to a higher energy
  state.
• http//earthguide.ucsd.edu/earthguide/diagrams/abs
  orption/absorption.html
• http//deal.unl.edu/jbutler/netc/jable2.htm

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Warm upPhotosynthesis

• Write the formula for photosynthesis.
• Where does photosynthesis take place in the
  cellbe specific.
• Light energy is converted into two molecules
  _____and ____
• Water is split into _____, ____ and ___

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Chemiosmosis and ATPpage 102

• Electrons provide the energy to pump H across
  the membrane. Then H diffuse across the
  membrane through the ATP synthase protein channel
  to form ATP.
  
• e_ H proton
  pump
• e_ e_
  H e_
• electron transport chain
• on thylk. membrane ATPsynthase
• ADP
  ATP
  
• H
• 
  

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2. Light Energy is Converted to Chemical Energy
(cont.)

• Photons are absorbed by photosystem I and boost
  electrons to a higher energy state.
• Reducing power (?) page 103
• NADP NADPH This is the reduced form
  that carries hydrogen and energy.
• The ATP and NADPH are released into the stroma.

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Diagram light energy conversion
e_
e_

• chlorop PSII
  electron transport chain
• chlorop.PSI ADP
  ATP
  
• NADP
  NADPH
• H20
• 02 HHe_ e _

H
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Wonderful Web
http//www.stolaf.edu/people/giannini/flashanimat/
metabolism/photosynthesis.swf
http//www.biology4all.com/resources_library/sourc
e/61a.swf
http//faculty.nl.edu/jste/noncyclic_photophosphor
ylation.htm
http//instruct1.cit.cornell.edu/Courses/biomi290/
MOVIES/OXYGENIC.HTML
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3. Calvin Cycle

• ATP and NADPH are used to make sugar.
• Calvin cycle occurs in the stroma.
• Carbon fixation enzymes attach carbon atoms
  from CO2 to build organic molecules.

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3. Calvin Cycle continued

• CO2 enters the cycle and a carbon attaches to a
  5-carbon compound (RuBP).
• This 6 carbon compound splits into two, 3-carbon
  compounds (PGA).
• ATP energy and NADPH reduce PGA to form the
  3-carbon PGAL. It is energized

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3. Calvin Cycle (finished)

• PGAL goes through a series of changes to form
  4-carbon and 5 carbon molecules.
• OR.a sugar. 3 turns form 6 PGALS and 5 are
  needed for RuBP and 1 for the sugar product.
• The Calvin cycle is dependent on ATP and NADPH

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Calvin Cycle Finale
CO2
6 C 3C PGA 3C PGA
RuBP 5 C
ATP ADP
ATP ADP
Calvin Cycle
5 C
NADPH NADP
4 C
PGAL 3C PGAL 3C
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Wonderful Web

• http//www.science.smith.edu/departments/Biology/B
  io231/calvin.htm
• http//faculty.nl.edu/jste/calvin_cycle.htm