The image shows a chloroplast, that's composed of:
A - outer membrane, that allows small molecules to get in and out of the cell;
B - stroma, the fluid filled inner space
C - granum, a stack of thylakoids
D - thylakoid, disks composed of protein and lipid.
The light dependent reactions of photosynthesis occurs in the thylakoids, when chlorophyll located in the thylakoid's membranes captures energy from the sun.
The Calvin cycle is a series of biochemical redox reactions that takes place in the stroma.
