Chloroplasts are the actual sites for photosynthesis. All green parts of a plant are involved in photosynthesis. Leaves are the most important organs of photosynthesis. In xerophytes like Opuntia, the stem is green and it performs photosynthesis. Over half a million chloroplasts are present in one square millimetre of a leaf. It measures about 4 to 6 micron. Atypical chloroplast of higher plants is discoid shaped.It is a double membrane bound organelle containing chlorophyll, carotenoid, xanthophyll, cytochrome, DNA, RNA, manganese, etc. Chloroplasts are generally considerably larger than mitochondria.The space enclosed by the envelope is filled with matrix called stroma. In the stroma, many grana are embedded. In each granum, several disc shaped lamellae are found. These disc shaped structures are called thylakoids. They resemble a stack of coins. This structure is known granum. Generally a chloroplast contains 40 to 60 grana. The photosynthetic pigments are found in grana. The stroma contains circular DNA, RNA and enzymes for starch synthesis.

chloroplast are the actual size for photosynthesis. Paul green parts of a plant are involved in photosynthesis. Les are the most important organ of photosynthesis. leaves are the. inside a force like.over half a million chloroplasts are present in on square millimetre of actual