Thylakoids are important
membrane proteins in the chloroplast that are responsible for harvesting light
during the first stage of photosynthesis where light-dependent reactions occur.
These thylakoids found in the stroma frequently form stacks of discs in an
alternating pattern of dark and light bands called grana that function as a
single compartment.
Thylakoid
membranes enclose thylakoid lumens that are responsible for phosphorylation
during photosynthesis. The thylakoid membrane is responsible for pumping protons
across the thylakoid lumen making the structure acidic with a pH 4.
