Photosynthesis Occurs in Two Phases: Light Dependent Phase Step 1: Chlorophyll absorbs a photon at Photosystem II and one of its electrons is kicked off onto an electron carrier molecule Step 2: Now lacking an electron, chlorophyll grabs one from a water molecule in the stroma, splitting the water into H+ and O 2 Step 3: The O2 diffuses out of the cell and is expired by the plant Step 4: H+ begins to build up in the stroma
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