Select targeted languages. 1  Catalan: fre m. 2  Chinese: Mandarin: ç¹«å¸¶ (zh), ç³»å¸¦ (zh) (jÃ¬dÃ i) 3  Finnish: frenulum. 4  Galician: freo (gl) m. 5  Greek: ÏÎ±Î»Î¹Î½ÏÏ (el) m (chalinÃ³s) 6  Icelandic: haft n. 7  Inuktitut: á¿áªááá (qillutaq)
Thylakoids float in the liquid filling the chloroplast, called the stroma. The part of the Thylakoids between two Grana is called a Lamella. Most importantly, they are the sites of the light-dependent reactions, which occur in the first step of photosynthesis.
Enclosed by the chloroplast membrane is the stroma, a semi-fluid material that contains dissolved enzymes and comprises most of the chloroplast's volume. Since, like mitochondria, chloroplasts possess their own genomes (DNA), the stroma contains chloroplast DNA and special ribosomes and RNAs as well.