eukaryotes have membrane-bound chloroplasts, shown in a transmission
electron micrograph on the left. Chloroplasts contain stacks of
thylakoid membranes (sometimes called grana). Embedded within these
thylakoid membranes are chlorophyll and other photosynthetic pigments.
The thylakoid membranes are suspended in the stroma, a protein rich
Photosynthetic prokaryotes, which lack membrane-bound organelles,
have invaginations of the cell membrane that serve a similar function
as thylakoid membranes. The prokaryote cytoplasm serves as stroma.