it looks like oxygen is being stolen from the water and so there would be no net gain with photosynthesis
The oxygen bound within water (H
2O) is physically present, but unavailable for use by aquatic organisms. Stated differently: The mere presence of water doesn’t mean that gill-breathers can survive in it – even though water (H
2O) obviously contains elemental oxygen.
Dissolved Oxygen – which is different from the oxygen that is bound within H
2O - is the crucial component required by gill-breathers. The photosynthetic process separates oxygen from the plant-absorbed water and releases it in a gaseous form – some of which often becomes “dissolved oxygen” within the surrounding water (the “universal solvent”) and is now available for use by gill-breathers. The exact percentage of the released O
2 that becomes dissolved in the water depends on many factors – especially the water’s temperature (warm water is less capable of holding dissolved oxygen than cooler water).
Bottom line: There’s no “net gain” in elemental oxygen following the photosynthetic process. However, some of the previously
unavailable oxygen (sourced from 12H
2O) is potentially rendered available for gill-breathers (as 6O
2).
6C
O2 +
12H
2O ---> C
6H
12O6 +
6O2 +
6H
2OBTW, an elemental "gain" is physically impossible in any reaction.
Instead, a reaction essentially reshuffles the cards - or elemental components - to yield different sequence-sets (i.e. compounds).if a plant is one that lives half in and half out of the water like a Parrots Feather are there two different things going in releasing oxygen?
Not sure what you're asking. But, the photosynthetic process is basically the same for submersed and emergent aquatic plants - and terrestrial plants. I suspect the only notable difference is
where their O
2 is released (into the water-column, versus above the water's surface and into the atmosphere).