( Just ( ( ( ( ( take ( a look ) ) ( at mitochondria ) ) , ) ( ( the organelle ) ( inside ( cells ( that ( serve ( as ( ( power plants ) ( to ( generate energy ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (ADVP (RB Just)) (VP (VB take) (NP (DT a) (NN look)) (PP (IN at) (NP (NN mitochondria))) (, ,) (NP (NP (DT the) (NN organelle)) (PP (IN inside) (NP (NP (NNS cells)) (SBAR (WHNP (WDT that)) (S (VP (VBP serve) (SBAR (IN as) (S (NP (NN power) (NNS plants)) (VP (TO to) (VP (VB generate) (NP (NN energy))))))))))))) (. .)))
Just take a look at mitochondria, the organelle inside cells that serve as power plants to generate energy.
(ROOT (S (NP (DT The) (NN mitochondria) (NNS organelles)) (VP (VBP are) (VP (VBN known) (PP (IN as) (NP (NP (DT the) (`` ``) (NN power) (NNS plants) ('' '')) (PP (IN of) (NP (DT the) (NN cell))))))) (. .)))