( ( Compounds ( useful ( for ( this purpose ) ) ) ) ( ( ( are again ) ( characterized ( by ( ( a ( polar group ) ) ( attached ( to ( a ( ( relatively high ) ( molecular ( weight ( hydrocarbon chain ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Compounds)) (ADJP (JJ useful) (PP (IN for) (NP (DT this) (NN purpose))))) (VP (VBP are) (ADVP (RB again)) (VP (VBN characterized) (PP (IN by) (NP (NP (DT a) (JJ polar) (NN group)) (VP (VBN attached) (PP (TO to) (NP (DT a) (ADJP (RB relatively) (JJ high)) (JJ molecular) (NN weight) (NN hydrocarbon) (NN chain)))))))) (. .)))
Compounds useful for this purpose are again characterized by a polar group attached to a relatively high molecular weight hydrocarbon chain.
(ROOT (S (NP (DT A) (NN lipid)) (VP (VBZ is) (NP (NP (CD one)) (PP (IN of) (NP (NP (DT a) (ADJP (RB highly) (JJ diverse)) (NN group)) (PP (IN of) (NP (NP (NNS compounds)) (VP (VBN made) (PRT (RP up)) (ADVP (RB mostly))))) (PP (IN of) (NP (NNS hydrocarbons))))))) (. .)))