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# Photosynthesis ## Site of Photosynthesis Green plant parts, especially leaves. - The mesophyll cells are located at (120-40°C) and are bound to chloroplasts, which are the sites of photosynthesis. ## Chloroplast - Outer membrane - Inner membrane - Inter-membrane space - Grana - Light-depende...

# Photosynthesis ## Site of Photosynthesis Green plant parts, especially leaves. - The mesophyll cells are located at (120-40°C) and are bound to chloroplasts, which are the sites of photosynthesis. ## Chloroplast - Outer membrane - Inner membrane - Inter-membrane space - Grana - Light-dependent reaction - Stroma - Light-independent reaction ## Types of Pigments - **Bright blue green** - Chlorophyll (Chla) - Chief pigment - **Yellow green** - Chlorophyll (Chlb) - Accessory pigment - **Xanthophyll** - Yellow - Accessory pigment - **Yellow-orange** - Carotenoid - Accessory pigment ## Photosystems Plants have two photosystems, which were named based on their order of discovery. - **Photosystem I (PS-I)** - Reaction centre (P700) - Light harvesting complex (LHC) / Antenna - Maximum absorption of 700nm of light - 100s of pigments and proteins - **Photosystem II (PS-II)** - Reaction centre (P680) - Hundred of pigments and proteins - Maximum absorption of 680nm of light ## Steps in Light-Dependent Reaction - Light absorption - Splitting of water molecules that result in the release of oxygen. - **ATP and NADPH are formed** ## Non-cyclic and Cyclic Photophosphorylation - **Non-cyclic photophosphorylation** - Is how ATP is formed in the light-dependent reaction - **Cyclic photophosphorylation** - Is how ATP is formed in the light-independent reaction