( ( ( Cellular respiration ) ( ( ( ( break down ) ( food ( such ( as sugar ) ) ) ) and ) ( release ( ( the energy ) ( they ( contain ( in ( a cell ) ) ) ) ) ) ) ) ( . ( This ( ( happens ( in ( both ( plant ( and ( animal cells ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SQ (NP (NNP Cellular) (NN respiration)) (VP (VP (VB break) (PRT (RP down)) (NP (NP (NN food)) (PP (JJ such) (IN as) (NP (NN sugar))))) (CC and) (VP (VB release) (NP (NP (DT the) (NN energy)) (SBAR (S (NP (PRP they)) (VP (VBP contain) (PP (IN in) (NP (DT a) (NN cell)))))))))) (. .) (NP (DT This)) (VP (VBZ happens) (PP (IN in) (NP (DT both) (NN plant) (CC and) (NN animal) (NNS cells)))) (. .)))
Cellular respiration break down  food  such as sugar and release the energy they contain in a cell. This happens in both plant and animal cells.
(ROOT (S (PP (IN As) (NP (NP (DT a) (NN result)) (PP (IN of) (NP (JJ cellular) (NN respiration))))) (, ,) (NP (NP (NN energy)) (PP (IN for) (NP (NN cell) (NNS processes)))) (VP (VBZ is) (VP (VBN released))) (. .)))