Cell Energy

1
Cell Energy
2
Useful Energy
3
Energy Flow
4
ATP
5
Light and Pigments

• In addition to water and carbon dioxide,
  photosynthesis requires light and CHLOROPHYLL

6
Light radiant energy from the sun, travels in
waves(light energy is measured in units called
photons)
amplitude
Crest high point
Baseline
amplitude
One wavelength
Trough low point
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• Amplitude height of wave distance between
  crest and/or trough (must use a reference point
  from which to start)
• Wavelength distance between where waves begin
  to repeat themselves
• Frequency how many waves pass a certain point
  in a given amount of time (high frequency vs. low
  frequency)

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Sunlight is a mixture of many different
wavelengths
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ROYGBV

• Colors in visible light spectrum
• Each of these has a different wavelength

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Figure 8-5 Chlorophyll Light Absorption
Section 8-2
Absorption of Light by Chlorophyll a and
Chlorophyll b
Chlorophyll b
Chlorophyll a
V
B
G
Y
O
R
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Pigments

• Substances in organisms that can absorb light
  (remember light must be absorbed before it can
  be converted and used by living systems)
• The color that you see is the one being REFLECTED
• CHLOROPHYLL is the major photosynthetic pigment
  in plants
• 2 types chlorophyll a directly involved in
  transformation of photons to chemical
  energy
• chlorophyll b helps trap other
  wavelengths and transfers it to chlorophyll a

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Accessory Pigments

• Other pigments that trap other wavelengths --
  found in chromoplasts
• Ex. Carotenoids
• xanthophyll yellows
• beta carotene oranges
• These are masked by presence of chlorophylls,
  except in autumn (when leaf cells stop
  synthesizing chlorophyll) fall colors
• Also is very obvious in ripe fruits, veggies
• Ex. Apple, tomato

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Photosynthesis