It's called hypoxemia, it's low levels of oxygen in the blood, to be more specific, it's oxygen loss in your blood from your arteries. It can cause respiratory disorders, and tissue hypoxia, as a result of the blood not providing much oxygen to your body.
I hope I helped :)
Before the Calvin cycle begins the energy is stored in bonds of ATP
The abdominal cavity is the answer you are looking for.
.........................................................ATP