Photosynthesis (Quiz 2) Flashcards
Respiration equation
6 O2 + C6H12O6 –> 6 CO2 + 6 H2O + ATP
Photosynthesis equation
6 CO2 + 6 H2O + (light) –> C6H12O6 + 6 O2
Fates of light after energy absorption (4)
fluorescence
conversion to heat
resonance transfer
e- donation
fluorescence =
release of excitation energy as a photon
energy conversion to heat =
energy is converted to heat, usually by accessory pigments
energy conversion to heat happens especially in
carotenoids
(energy conversion to heat) when a molecule…
(especially a pigment) absorbs light energy, an e- can get excited (jumps from ground state to excited state)
when an e- jumps to excited state…
the rest of the energy…
it goes from a higher excited state to a lower excited state (this little bit of energy is lost as heat) (always happens)
the rest of the energy must be released as fluorescence
fluorescence is always
at a lower wavelength than the higher ES
which electrons get excited
the ones in the molecular orbitals
carotenoids & other accessory pigments absorb
“excess light” & convert it to heat
resonance transfer =
excitation energy being transferred from one molecule to another
examples of resonance transfer
chl a gets energy from chl a or chl b molecules, & carotenoids
electron donation =
(last step) redox rxns that lead to light dependent reactions (molecule that donates e- after getting excited)
electron donation via
trap chlorophyll (traps excitation energy & uses it for redox rxns)
