( They ( ( are ( ( most abundant ) ( in ( ( ( cells ( with ( high ( energy needs ) ) ) ) , ) ( such ( as ( ( ( muscle cells ) , ) ( brain cells ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBP are) (ADJP (ADJP (RBS most) (JJ abundant)) (PP (IN in) (NP (NP (NNS cells)) (PP (IN with) (NP (JJ high) (NN energy) (NNS needs))) (, ,) (PP (JJ such) (IN as) (NP (NP (NN muscle) (NNS cells)) (, ,) (NP (NN brain) (NNS cells)))))))) (. .)))
They are most abundant in cells with high energy needs, such as muscle cells, brain cells.
(ROOT (S (NP (DT All) (NNS cells)) (VP (VBP share) (NP (DT the) (NN characteristic)) (SBAR (IN that) (S (NP (PRP they)) (VP (VBP need) (NP (NN energy)))))) (. .)))
All cells share the characteristic that they need energy.