Describe the structure of a typical eukaryotic chloroplast.
Two membranes, approximately 3000 angstroms in total thickness, surround chloroplasts. Every layer is 40-60 Angstrom wide. The inner membrane is highly detailed to produce a lamellar structure. Internally, the chloroplasts are divided into two sections: (a) the stroma, which is a colorless, granular material; and (b) the membrane system, which is made up of closed flattened sacs known as thylakoids. These thylakoids are clumped together and resemble heaps of coins. Grana is the name given to these buildings. The arrangement can take the shape of simple parallel sacs running longitudinally, or it can take the form of a complicated interconnected network of sacs. In algae, starch granules in the chloroplasts usually congregate around a specific area known as the pyrenoid.
