What do chloroplasts contain? Explain the structure of chloroplast in brief.

Explanation

Chloroplast is a double-membrane structure in which the outer membrane is more permeable than inner membrane.
The inner membrane possesses more proteins.
The outer membrane may be attached to ER.
The chloroplast contains a ground substance known as matrix or stroma which is a semi fluid, colourless and colloidal complex. Stroma contains DNA and RNA. Membrane bound, flat sac-like structures called thylakoids run through the stroma. These thylakoids are arranged one above the other and this stalk of thylakoids is called grana. The grana contain chlorophyll and other pigments and are capable of trapping the solar energy.