Some notes on the carbon cycle

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Some notes on the carbon cycle

• 29 Jan 2009
• BIOL 114

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Quiz

• The majority of actual of actual weight (biomass)
  gained by plants as they grow comes from which of
  he following substances
• Organic substances in soil that are taken up by
  plant roots.
• Carbon dioxide in the air that enters through
  leaf stomata.
• Minerals dissolved in water taken up by plant
  roots.
• Energy from the sun captured by leaves.
• Carbon from decomposed leaf litter in soil.

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Quiz (cont.)

• 2. What are the different pathways that a carbon
  atom can take once it is inside a plant? Choose
  all that are correct.
• It can exit the plant as CO2.
• It can become part of the plant cell walls,
  protein, fat, DNA.
• It can be consumed by an insect feeding on the
  plant and become part of the insects body.
• It can exit the soil as CO2 as plant tissue
  decomposes.

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550 Million Years of CO2 and Temperature data
Keeling curve
Land plants first evolve
Ferns
Earth is so cold, massive die-off Then seed
plants evolve
Flowering plants
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Plant chemical composition

• Plant macronutrients (percent by weight)
• C Carbon 45
• H Hydrogen 6
• O Oxygen 45
• P Phosphorus 0.2
• K Potassium 1
• N Nitrogen 1.5
• S Sulfur 0.1
• Ca Calcium 0.5
• Mg Magnesium 0.2

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Plant chemical composition

• Plant macronutrients (percent by weight)
• C Carbon 45
• H Hydrogen 6
• O Oxygen 45
• P Phosphorus 0.2
• K Potassium 1
• N Nitrogen 1.5
• S Sulfur 0.1
• Ca Calcium 0.5
• Mg Magnesium 0.2

Photosynthesis 6CO2 6H20 sunlight ? C6H12O6
6O2 What do plants do with C6H12O6?
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Plant chemical composition

• Plant macronutrients (percent by weight)
• C Carbon 45
• H Hydrogen 6
• O Oxygen 45
• P Phosphorus 0.2
• K Potassium 1
• N Nitrogen 1.5
• S Sulfur 0.1
• Ca Calcium 0.5
• Mg Magnesium 0.2

Photosynthesis 6CO2 6H20 sunlight ? C6H12O6
6O2 What do plants do with C6H12O6? Respirati
on 6C02 6H20 energy ? C6H12O6 6O2 Basic
building block Cellulose (wood) C6H12O6 -
C6H12O6 - C6H12O6 - C6H12O6 ca. 75 of a
plants biomass comes from the air!
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True or False?

• Global warming will make all parts of the earth
  warmer
• Increased atmospheric CO2 will always increase
  productivity of plants
• P. 317
• Carbon moves through different pools at the same
  rate
• Figure 3.
• The largest pools of carbon are on land and in
  living organisms
• Figure 2.
• Photosynthesis provides energy for uptake of
  carbon and nutrients through plant roots
• Figure 3 p. 317.
• Plants get their biomass from nutrients in the
  soil
• P. 315-316.
• Soil respiration means the soil is respiring
  rather than the organisms that live in the soil
• P. 315-316
• Plant cells do not undergo respiration, only
  animal cells respire
• P. 315

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For Next Tuesday

• Download and read Climate Change Impacts and
  Solutions for Pennsylvania (Union of Concerned
  Scientists)
• In your groups
• Divide up the paper by major sections
• Each student should read the whole paper but
  become and expert on one section
• Next Tuesday, well discuss the paper in groups
  and in class.