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.
The outer layer of the double membrane is much more permeable than the inner layer, which features a number of embedded membrane transport proteins. 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.