Although the stroma contains DNA and ribosomes, most of the organelle's proteins originate from the cell nucleus and ribosomes.

-Grana (Granum): stacks of thylakoids stringed together by interconnecting Thylakoid membranes, or Thylakoid channels.

-Thylakoid: sub-organelles with a flattened disc shape, within them is an empty space called the Thylakoid lumen; photosynthesis takes place on the Thylakoid membrane.