Chloroplasts PP3

Spinacia oleracea is a hardy leafy annual of the amaranth family (Amaranthaceae), a commonly used vegetable in the world, commonly referred to as spinach. Deep within the cells of these spinach leaves lies chloroplasts, a type of organelle characterized by its two membranes and a high concentration of chlorophyll. They are structures by which photosynthesis, the process by which carbohydrates are made from carbon dioxide and water in the presence of chlorophyll, use energy captured from sunlight by chlorophyll. This results in the production of oxygen and energy-rich organic compounds. Chloroplasts contain thylakoids, flattened sacs. Light energy (sunlight) reaching the thylakoids excites the chlorophyll pigments, causing them to drive electrons and hydrogen from water to NADP+, an electron acceptor. The electrons enter the electron transport chain, resulting in the products of ATP and NADPH (converted from NADP+). These are then used in the light-independent reactions of photosynthesis, where carbon dioxide and water are used to make organic compounds.