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Plant bio
Photosynthesis
Question | Answer |
---|---|
What is photosynthesis? | Light dependent assimilation of CO2 |
Where does it occur globally? | ie. N. Atlantic spring bloom El nino Pacific phytoplankton bloom (equator) |
Energy of light | Irradiance: mass solar output, energy at earth's surface Energy of light: E= hv h = Planck’s constant v = frequency = c/λ |
Light in forests | - canopy top: 400nm plus - beneath canopy: 700nm into far red |
Why are leaves green? | - reflected light - chlorophyll absorbs red and blue mostly |
How is the energy of light absorbed used? | - higher excited state from blue light absorption - lower excited state from red light absorption and heat loss - red flourescence from this lower energy state |
How is energy conserved? | Energy is transferred between pigments to a reaction center where electron transfer occurs, and ultimately to chlorophyll by FRET |
What is the enhancement effect? | - synergy between red and far red irradiation explained by photosystems I and II - both contain chlorophyll pigments - I absorbs longer wavelengths, II absorbs shorter wavelengths |
Z scheme of electron transport | - light-dependent transfer of e- from water to NADP+ - Movement of electrons is coupled to transfer of protons across thylakoid membrane – stroma to lumen - generates H+ gradient that is dissipated by F1-ATPase, producing ATP |