atrazine and the electron transport chain atrazine is one of the most widely used agricultural pesticides. atrazine kills plants by binding to a component of the electron transport chain on the thylakoid membrane on photosystem ii. atrazine prevents electrons from passing along the electron transport chain causing all downstream electron carriers to stay in an oxidized form (lodish, 2004.) the major claim of atrazine is that atrazine prevents electron flow in photosystem ii. how could you test this idea that atrazine affects electron flow in the photosystems and not the calvin cycle?