( ( ( ( ( ( The brain ) ( ( needs glucose ) ( ( ( ( to function ) , ) and ) ( by ( not ( eating ( enough carbohydrates ) ) ) ) ) ) ) , ) not ) ( ( enough glucose ) ( is produced ) ) ) . )
(ROOT (S (S (NP (DT The) (NN brain)) (VP (VBZ needs) (NP (NN glucose)) (PP (PP (TO to) (NP (NN function))) (, ,) (CC and) (PP (IN by) (S (RB not) (VP (VBG eating) (NP (JJ enough) (NNS carbohydrates)))))))) (, ,) (RB not) (S (NP (JJ enough) (NN glucose)) (VP (VBZ is) (VP (VBN produced)))) (. .)))
The brain needs glucose to function, and by not eating enough carbohydrates, not enough glucose is produced.
(ROOT (S (NP (NNP Glucose)) (VP (VBZ is) (NP (NP (DT a) (NN carbohydrate)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (VP (VBN produced) (PP (IN by) (NP (NN photosynthesis))))))))) (. .)))