Photosynthesis occurs in plants and some protists. 
In the cytoplasm inside the cell are chloroplasts
which is where photosynthesis and some ATP synthesis occurs.
Inside the chloroplast are the thylakoid membranes 
which look like stacked little green pancakes. 
which is where the beginning of photosynthesis occurs. 
The stroma is empty space in the chloroplast
where the light independent reaction occurs
Light goes into the cell from the sun and the photons,
which make up light excite the electrons 
in the thylakoid membranes
The excited electrons then gothrough the electron transport chain
and give off their excited energy to the array of enzymes there. 
 
H2O molecules enter the chloroplast and through photolysis break apart into
two hydrogen molecules and one oxygen molecule 
The hydrogen molecules go into the ATP Synthase
which is an enzyme in the electron transport chain
that makes ATP
and the hydrogen molecules help to make ATP. 
Two oxygen molecules from the H2O molecules 
bond together to make oxygen gas 
which is O2, which exits the chloroplast and goes out into the cell. 
NADPH and ATP exits the thylakoid membranes
and go out into the stroma
the process in the thylakoid membrane is the Light Dependent Reaction
Carbon Dioxide comes into the cell from another source
such as the atmosphere or someone's dirty breath
and then carbon dioxide attaches to the enzyme Rubisco 
And forms two PGA molecules
Each PGA molecule get a phosphate group from
the ATP, which become ADP+Pi
and a hydrogen comes from NADPH 
which becomes NADP
the two PGA molecules form two molecules of PGAL
which bonds together to make a 6-carbon sugar
like glucose, which is sent out of the chloroplast. 
The Rubisco is regenerated and is just waiting to be used again!
The ADP+ Pi and NADP go back into the thylakoid membranes  
to be utilized again
This is know as the Light Independent Reaction
