Chloroplast

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Chloroplast

• responsible for photosynthesis.
• contains a permeable outer membrane, a less
  permeable inner membrane, a intermembrane space,
  and an inner section called the stroma.
• larger than the mitochondria
• not folded into cristae.
• forms a series of flattened discs, called the
  thylakoids.

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• http//www.mhhe.com/biosci/genbio/tlw2/student/olc
  /graphics/johnson2tlw_s/ch08/others/mi08-04b.dcr

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• The innermost membrane of the chloroplast is
  called the thylakoid membrane.
• The thylakoid membrane is folded upon itself
  forming many disks called grana (singular
  granum).
• The "cytoplasm" of the chloroplast is called the
  stroma

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Chlorophyll

• Chlorophyll is a complex molecule. Several
  modifications of chlorophyll occur among plants
  and other photosynthetic organisms.

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Chlorophyll a

• All photosynthetic organisms (plants, certain
  protistans, prochlorobacteria, and cyanobacteria)
  have chlorophyll a.

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• Chlorophyll a absorbs its energy from the
  Violet-Blue and Reddish orange-Red wavelengths,
  and little from the intermediate
  (Green-Yellow-Orange) wavelengths.
• Chlorophyll A is the main photosynthetic pigment
  in all organisms except bacteria.

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Accessory pigments

• Accessory pigments absorb energy that chlorophyll
  a does not absorb. Accessory pigments include
  chlorophyll b (also c, d, and e in algae and
  protistans), xanthophylls, and carotenoids (such
  as beta-carotene).

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Compare wavelength absorbed

• 1. Chlorophyll a Light to medium green. Main
  photosynthetic pigment.
• 2. Chlorophyll b Blue-green. Accessory Pigment.
• 3. Carotene Orange. Accessory Pigment.
• 4. Xanthophyll Yellow. Accessory Pigment.

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Action and Absorption Spectrum

• Go to this site to learn more about these.
• Action Absorption Spectra

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Action Spectra page 77

• The use of action spectra has been central to the
  development of our current understanding of
  photosynthesis. An action spectrum is a graph of
  the magnitude of the biological effect observed
  as a function of wavelength. Examples of effects
  measured by action spectra are oxygen evolution

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Action Spectrum page 77
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Absorption Spectrum page 77

• An absorption spectrum the wavelengths at which
  it can absorb light and enter into an excited
  state. The diagram represents the absorption
  spectrum of pure chlorophylls

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• http//academic.kellogg.edu/herbrandsonc/bio111/an
  imations/0053.swf

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Photoexcitation

• When a pigment absorbs a photon, one of the
  molecules electrons is elevated to an orbital
  with more potential energy (this excited state
  unstable).
• Only photons absorbed are those whose energy is
  exactly equal to the energy difference between
  the ground state and the excited state. This
  energy difference varies between pigments.

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Stages of Photosynthesis page 78

• The first process is the Light Dependent Process
  (Light Reactions), requires the direct energy of
  light to make energy carrier molecules that are
  used in the second process.
• Untitled Document

• Harvesting Light
• http//www.biology4all.com/resources_library/sourc
  e/61a.swf
• Animation Quizzes (go to light independent
  reaction)
• NetLearning - Examples - Flash

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There are two paths which can be taken

• Cyclic electron flow The simpler, involving
  only photosystem 1 and generates only
  ATP Animations
• Non cyclic uses both systems, generates ATP and
  NADPH and oxygen is released.
• Light-dependent reactions (scroll down to
  animations)

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Photophosphorylation page 78 study guide

• The electron transport system is found embedded
  within the thylakoid membrane and functions in
  the production of ATP. The system contains
  membrane-bound electron carriers that pass
  electrons from one to another. As a result of
  gaining an electron (reduction), the first
  carrier of the electron transport system gains
  energy. It uses some of the energy to pump H
  into the thylakoid.

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• ATP is produced from ADP and Pi when hydrogen
  ions pass out of the thylakoid through ATP
  synthase. This method of synthesizing ATP by
  using a H gradient in the thylakoid is called
  photophosphorylation.
• Light reactions
• Animations
• Tutorial 8.2 Photophosphorylation

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One more look

• http//www.fw.vt.edu/dendro/forestbiology/photosyn
  thesis.swf

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The Calvin cycle

• occurs in the stroma of chloroplasts
• Carbon dioxide is captured by the chemical
  ribulose biphosphate (RuBP).
• RuBP is a 5-C chemical.
• Six molecules of carbon dioxide enter the Calvin
  Cycle producing one molecule of glucose.

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Carbon fixation page 79

• The words "CO2 fixation" refer to the attachment
  of CO2 to an organic compound each CO2 binds to
  a 5-carbon ribulose biphosphate (RuBP) molecule.
• Carbon dioxide fixation is catalyzed by RuBP
  carboxylase (rubisco).

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Page 79 study guide

• Read study guide on Calvin cycle
• calvin

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• Calvin cycle
• calvin
• photosynthesis dark phase
• Garrett Grisham Biochemistry
• http//academic.kellogg.cc.mi.us/herbrandsonc/bio1
  11/animations/0055.swf
• Calvin Benson

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• For each six CO2 molecules that enter the cycle
  one glucose molecule is produced.
• About 30 of the energy available in ATP and
  NADPH is finally present in the glucose produced.

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Comparison of Photosynthesis and Respiration
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Limiting Factors in Photosynthesispage 81

• Temperature plays a role in affecting the rate of
  photosynthesis. Enzymes involved in the
  photosynthetic process are directly affected by
  the temperature of the organism and its
  environment

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• Light Intensity is also a limiting factor, if
  there is no sunlight, then the photolysis of
  water cannot occur without the light energy
  required.

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• Carbon Dioxide concentration also plays a factor,
  due to the supplies of carbon dioxide required in
  the Calvin cycle stage.

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• This is the chapter lecture outline for chapter
  10 of your book.
• Chapter Ten Extended Lecture Outline
• This review goes along with your book Chapter 10
  eLearning Session

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