Where does that light come from?
This one:
Is it your wild fiction that the reaction AND its immediate environment contradict the second law? Even after it was pointed out to you - that such fiction does not work in real life???
hint:
During
formation of glucose the system is gaining energy – so Δ
G is positive – Endergonic, non-spontaneous. To occur at all it must be “pushed or pulled” by associative Exergonic reaction – energy input from its surroundings.
Endergonic reactions can be achieved if they are either
pulled or
pushed by an
exergonic (stability increasing, negative change in
free energy) process. Of course, in all cases the net reaction of the
total system (the reaction under study plus the puller or pusher reaction) is exergonic.
All physical and chemical systems in the universe follow the
second law of thermodynamics and proceed in a downhill, i.e.,
exergonic, direction. Thus, left to itself, any physical or chemical system will proceed, according to the second law of thermodynamics, in a direction that tends to lower the
free energy of the system (Δ
G is negative), and thus to expend energy in the form of work.
The
energy transfer available in the immediate surrounding (proximity - touching the plant) when combined with the reaction for forming glucos is still a net increase in entropy
And of course - when a photosystem absorbs a photon, the internal energy (
U =
hν0) of the photon is converted into the free energy of the chlorophyll excited state (Δ
G)
and some part of the energy is expected to be converted into entropy (ΔS),
===========================================
- Photosystem I, non-cyclic electron flow path:
2Chlorophyll + 2γ(700 nm) -> 2Chlorophyll + NADPH + ATP+ H 2 O
cyclic electron flow path:
2Chlorophyll + 2γ(700 nm) -> 2Chlorophyll + ATP+ H 2 O
- Photosystem II:
H 2 O + 2γ(680 nm) + 2Chlorophyll -> 2Chlorophyll + 1/2 O 2 + 2H+
- Calvin Cycle:
6CO 2 + 12NADPH + 18ATP + 12H 2 O -> C 6 H 12 O 6
===================In summary -
PII - Photosystem II:
PI - Photosystem I:
12 PII + 12PI(non-cyclic) + 6PI(cyclic) + Calvin Cycle
give us
6CO 2 + 24H 2 O + 60γ -> C 6 H 12 O 6 + 6O 2 + 18H 2 O.
"We can of course see now how the biome functions thermodynamically. It requires a great deal of energy input in the form of light, and the
cumulative generation of entropy, first during the photosynthesis of glucose, and then through the respiration of glucose back into carbon dioxide and water (not to mention all of the other processes of life which go into circulating glucose through the biome) guarantees that the entropy always increases.
This relentless increase in entropy, along with the
conservation of energy (in terms of heat, internal energy and work) make up the two "laws" of thermodynamics."
That would be your fictional world. You are the one who claimed that entropy always increases. Going from water and carbon dioxide to carbohydrates is a decrease in entropy.
A "decrease in entropy" for what? the reaction AND its immediate environment?
That answer that is always - "no".
In your fictional world, photosynthesis violates the 2nd law.
Also, did you miss this part?
"It requires a great deal of energy input in the form of light"
Where does that light come from?
There are a great many reactions that result in photons emitted - not just fusion of Hydrogen... as it turns out.
Notice that in "white light" not all photons are at γ(700 nm)
