( ( ( The ( heme-iron moiety ) ) ( of ( the ( hemoglobin molecule ) ) ) ) ( ( allows ( ( ( binding and ) release ) ( of ( ( oxygen , ) ( ( dependent ( upon ( the ( partial oxygen ) ) ) ) ( tension ( ( to which ) ( ( the hemoglobin ) ( is exposed ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ heme-iron) (NN moiety)) (PP (IN of) (NP (DT the) (NN hemoglobin) (NN molecule)))) (VP (VBZ allows) (NP (NP (VBG binding) (CC and) (NN release)) (PP (IN of) (NP (NP (NN oxygen)) (, ,) (NP (ADJP (JJ dependent) (PP (IN upon) (NP (DT the) (JJ partial) (NN oxygen)))) (NN tension) (SBAR (WHPP (TO to) (WHNP (WDT which))) (S (NP (DT the) (NN hemoglobin)) (VP (VBZ is) (VP (VBN exposed)))))))))) (. .)))
The heme-iron moiety of the hemoglobin molecule allows binding and release of oxygen, dependent upon the partial oxygen tension to which the hemoglobin is exposed.
(ROOT (S (NP (NNP Hemoglobin)) (VP (VBZ is) (NP (NP (DT a) (NN carrier) (NN molecule)) (SBAR (WHNP (WDT that)) (S (VP (VBZ becomes) (ADJP (RBR less) (JJ effective) (PP (IN at) (NP (NP (VBG binding) (NN oxygen)) (PP (IN as) (NP (NN temperature) (NNS increases))))))))))) (. .)))