Overview • Chloroplasts are organelles that convert energy to forms that cells can use for work • chloroplasts: from sunlight to ATP & carbohydrates • ATP = active energy • carbohydrates = stored energy
Chloroplasts • Chloroplasts are plant organelles • chloroplasts • store chlorophyll & function in photosynthesis • in leaves, other green structures of plants & in eukaryotic algae
Chloroplasts • Function • photosynthesis • generate ATP & synthesize sugars • transform solar energy into chemical energy • produce sugars and oxygen from CO2 & H2O
Structure of a Chloroplast • Structure • 2 membranes • outer membrane • inner membrane
Structures of a Chloroplast • Thylakoid- system of membrane that is arranged in flattened sacs • Light reactions take place in the Thylakoids. • Chemiosmosis takes place across the membrane of a Thylakoid.
Structures of a Chloroplast • Granum (grana is plural) – stack of connected and layered thylakoids
Structures of a chloroplast • Stroma- solution that surrounds the grana The Calvin Cycle (light- independent reactions) takes place in the stroma.
Why are chloroplasts green?? • Chloroplasts contain a green pigment called chlorophyll. This is what makes plants green • Chlorophyll has a green pigment • Pigment = a substance which produces a characteristic color as a result of the color (of light) being reflected because of its wavelength