( ( ( Green plants ) ( ( ( break down ) ( ( water ( -LRB- ( and ( ( carbon dioxide ) -RRB- ) ) ) ) ( during photosynthesis ) ) ) ( to ( produce ( ( oxygen and ) ( the ( simple sugars ) ) ) ) ) ) ) ( they ( ( require ( for energy ) ) . ) ) )
(ROOT (S (S (NP (NNP Green) (NNS plants)) (VP (VBP break) (PRT (RP down)) (NP (NP (NP (NN water)) (PRN (-LRB- -LRB-) (CC and) (NP (NP (NN carbon)) (NP (NN dioxide))) (-RRB- -RRB-))) (PP (IN during) (NP (NN photosynthesis)))) (S (VP (TO to) (VP (VB produce) (NP (NP (NN oxygen)) (CC and) (NP (DT the) (JJ simple) (NNS sugars)))))))) (NP (PRP they)) (VP (VBP require) (PP (IN for) (NP (NN energy)))) (. .)))
Green plants break down water (and carbon dioxide) during photosynthesis to produce oxygen and the simple sugars they require for energy.
(ROOT (S (S (NP (NNS Photosynthesis)) (VP (VBZ is) (VP (VBN described) (PP (IN by) (NP (DT this) (NN statement)))))) (: :) (S (NP (NP (NN carbon) (NN dioxide)) (CC and) (NP (NN water))) (VP (VBP are) (VP (VBN turned) (PP (IN into) (NP (NN sugar) (CC and) (NN oxygen)))))) (. .)))
Photosynthesis is described by this statement: carbon dioxide and water are turned into sugar and oxygen.