Chloroplasts

• Chloroplasts


  Organelles where photosynthesis takes place
• Chloroplasts are found in plant cells that carry out photosynthesis, not in parts of the plant that do not photosynthesize like the roots
• Photosynthesis


  Light energy is used to react carbon dioxide with water to form oxygen and the carbohydrate glucose
• Light dependent reactions


  Use chlorophyll to harvest light energy, transfer energy into chemical bonds of other molecules like ATP
• Light independent reactions


  Reactions in which glucose is formed, do not require light
• Chloroplasts


  • Surrounded by a double membrane
  • Contain membrane-bound flattened discs called thylakoids
  • Thylakoids are stacked into structures called grana
  • Grana are connected by flattened membranes called lamellae
  • Contain a fluid material called the stroma
• Thylakoids


  Where the light dependent reactions take place, contain chlorophyll and enzymes
• Stroma


  Where the light independent reactions take place, contains enzymes
• Starch granules


  Carbohydrate glucose produced in photosynthesis can be converted to and stored as starch
• Chloroplasts


  • Contain a loop of DNA that encodes some of the proteins needed for photosynthesis
  • Contain ribosomes that synthesize the proteins encoded by the chloroplast DNA