The Chloroplast

• the chlorophyll is arranged in a system of flattened membranes called thylakoids
• the thylakoids contain a system of electron carriers and associated enzymes involved in photosynthesis 
• thylakoids are arranged in stacks of membranes called grana and are linked together by intergranal lamallae
• as the grana contains concentrated areas of light absorbing photopigments, much of the light harvesting takes place at these points
• carbon dioxide is used (fixed) and sugars and other compounds are made in a cyclical series of reactions in the stroma 
• the reactions that take place in the stroma are dependent on a steady supply of products from the reactions in the thylakoids