Definition of thylakoid in English:



  • Each of a number of flattened sacs inside a chloroplast, bounded by pigmented membranes on which the light reactions of photosynthesis take place, and arranged in stacks or grana.

    as modifier ‘thylakoid membranes’
    • ‘Chloroplast envelopes, stacked grana and unstacked stroma thylakoids were well-defined.’
    • ‘Affected leaf tissue is white and the plastids lack thylakoids and chlorophyll.’
    • ‘The pigment proteolipids of thylakoids have both a photosynthetic function and a role in membrane structure.’
    • ‘This organelle contains a complex membrane system, the thylakoids, in which the photosynthetic machinery is located.’
    • ‘Chloroplasts at the proximal end of the cell also have grana, but with up to nine thylakoids per stack.’



/ˈTHīləˌkoid/ /ˈθaɪləˌkɔɪd/


1960s from German Thylakoid, from Greek thulakoidēs ‘like a pouch’, from thulakos ‘pouch’.