Chapter 6

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Chapter 6 7 Photosynthesis and Respiration
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I. ENERGY The ability to do work

• A. Why do cells need energy?
• 1) Active Transport
• 2) Cell division, growth and development
• 3) To make macromolecules- proteins,
  carbohydrates, etc.
• 4) To build cell parts-extra cellular
  membranes

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• B. Two classifications of organisms based upon
  how they obtain energy
• 1) Autotrophs (producers) organisms that can
  make their own food( glucose) example plants

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Autotrophs
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• 2) Heterotrophs (consumers) organisms that
  obtain food from other sources example animals
  and fungi

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Heterotrophs
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C. Pathway of Energy

• photosynthesis
  cellular respiration
• Sun? autotrophs ? food(glucose)?
  heterotrophs? ATP

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• D. Cellular Energy ATP Adenosine Triphosphate
• Removes phosphate
  Removes phosphate
• Release energy
  Release energy
• ATP is like a rechargeable battery

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Overview of photosynthesis and respiration
SUN
RADIANT ENERGY
CELL ACTIVITIES
PHOTOSYNTHESIS
RESPIRATION
GLUCOSE
ATP(ENERGY)
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E. Photosynthesis 2 RXNS

• Light-Independent Reactions

• Light-Dependent Reactions

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II. PHOTOSYNTHESIS PHOTO light SYNTHESIS to
make

• Process by which solar energy is converted to
  cellular energy (ATP) and stored food (glucose)
• Overall Reaction sunlight
• 6 CO2 6 H20 ? C6H12O6 6 O2
• chlorophyll
• Occurs in the chloroplasts of plant cells
• Solar E is converted by the use of pigment,
  molecules that absorb certain wavelengths of
  light and reflect (what we see) others.

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• Chlorophyll main photosynthetic pigment, absorbs
  red blue light, reflects green
• Accessory pigments
• Carotenes absorb blue green, reflect yellow
  and orange.
• In fall, chlorophyll is broken down so we see the
  colors of the accessory pigments.

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Photosynthesis consists of two phases

• 1) Light Reactions the photo part
• Solar energy converted to cellular energy (ATP)
• Chlorophyll captures (absorbs) light
• Water is split, releasing oxygen gas
• Occurs in the thylakoid membranes of the
  chloroplast

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• 2) Calvin Cycle the synthesis part
• Energy from light reactions used to fix CO2
  into glucose (C6H12O6)
• Occurs in the stroma of the chloroplast.
• Called Dark or light independent Reactions

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• In hot dry conditions plants loose water through
  stomata which are small pores usually located on
  the undersurface of leaves
• They close these to prevent water loss

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The rate of photosynthesis is affected byLight
intensity, carbon dioxide levels, temperature
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E. Photosynthesis 2 RXNS

• Light-Independent Reactions

• Light-Dependent Reactions

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Link between photosynthesis and respiration
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EQUATION FOR PHOTOSYNTHESIS
WATER
OXYGEN
6CO2
6H2O
ENERGY
C6H12O6
6O2
CARBON DIOXIDE
GLUCOSE
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EQUATION FOR RESPIRATION
CARBON DIOXIDE
ATP
GLUCOSE
C6H12O6
6O2
6CO2
6H2O
ENERGY
OXYGEN
WATER
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III. CELLULAR RESPIRATION

• A series of chemical reactions that release
  energy by breaking down glucose and making H2O
  and CO2.
• Overall Reaction
• C6H12O6 6 O2 ? 6 CO2 6 H20
• Glucose is the primary source of energy at the
  cellular level. The stored energy in its bonds
  will be converted to cellular energy in the form
  of ATP.

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Cellular respirationOccurs in the
mitochondria
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PATHWAYS OF GLYCOLYSIS RESPIRATION

• Diagram