1. Membrane: Each chloroplast is covered by a bilayer membrane. Outer cover and inner cover. The outer layer is called the outer layer and the inner layer is called the inner layer. The space between the two coats is called the periplastidal space. Distance of periplastidal space is 6-8 nm. The outer coat contains porin proteins.
2. Stroma: The transparent, granular and semi-fluid material inside the chloroplast is called stroma. It is a colloidal and hydrophilic liquid. The stroma contains about 200 DNA, RNA and circular DNA or plasmids. It contains protein plastogaebuli, osmophilic granules, sugar, oil droplets, vitamins, mineral salts etc.
3. Thylakoid: The sac-shaped three-dimensional structure in the stroma is called thylakoid. It is called the structural and functional unit of chloroplast. Its width is 100-300 Å.
4. Granum: 10-100 thylakoids arranged in a row forming a stack is called granum. Some quantosomes are present on the inner surface of the granum cycle membrane. Each chloroplast contains 40-60 grana.
5. Stroma lamellae: Two adjacent thylakoids are connected by ducts called stroma lamellae or intergranular frets. Stroma lamellae contain chlorophyll.
6. ATP Synthase: The round or oval object in the thylakoid membrane is called ATP synthase. It contains enzymes for making ATP. It makes ATP for cells.
7. Photosynthetic Unit: Photosynthetic units are present on the thylakoids. It is called photosynthetic unit. Each photosynthetic unit contains 300-400 molecules of chlorophyll-a, chlorophyll-b, carotene and xanthophyll. It contains various enzymes, phospholipids, sulfolipids, metal ions, quinones, etc.
8. DNA: Chloroplasts contain short and circular DNA. DNA has its own characteristics. This is called chloroplastic DNA. Each chloroplast contains 200 cpDNA. Without cpDNA, photosynthesis cannot occur in chloroplasts.
9. Ribosomes: Chloroplasts contain 70S ribosomes. It synthesizes proteins.
10. Unidentified granules: Chloroplasts contain some unidentified granules.