( Mitochondria ( ( ( are sometimes ) ( ( ( called ( ( the ( ` ( power ( stations ' ) ) ) ) ( of ( ( the cell ) ( because ( they ( ( ( ( burn up ) ( food molecules ) ) , ) ( in ( ( the presence ) ( of oxygen ) ) ) ) ) ) ) ) ) ) , ) ( to ( ( release energy ) ( in ( ( a process ) ( called ( aerobic respiration ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Mitochondria)) (VP (VBP are) (ADVP (RB sometimes)) (VP (VBN called) (NP (NP (DT the) (`` `) (NN power) (NNS stations) ('' ')) (PP (IN of) (NP (NP (DT the) (NN cell)) (SBAR (IN because) (S (NP (PRP they)) (VP (VBP burn) (PRT (RP up)) (NP (NN food) (NNS molecules)) (, ,) (PP (IN in) (NP (NP (DT the) (NN presence)) (PP (IN of) (NP (NN oxygen))))))))))) (, ,) (S (VP (TO to) (VP (VB release) (NP (NN energy)) (PP (IN in) (NP (NP (DT a) (NN process)) (VP (VBN called) (NP (JJ aerobic) (NN respiration)))))))))) (. .)))
Mitochondria are sometimes called the 'power stations' of the cell because they burn up food molecules, in the presence of oxygen, to release energy in a process called aerobic respiration .
(ROOT (S (NP (JJ Aerobic) (NN respiration)) (VP (VBZ has) (NP (NP (DT the) (NN advantage)) (PP (IN of) (S (VP (VBG releasing) (NP (JJR more) (NN energy))))))) (. .)))