( ( ( Lignin ( -LRB- ( n. -RRB- ) ) ) ( ( A substance ) ( ( ( characterizing ( wood cells ) ) and ) ( ( differing ( from ( cellulose ( in ( its conduct ) ) ) ) ) ( with ( certain ( chemical reagents ) ) ) ) ) ) ) . )
(ROOT (NP (NP (NP (NNP Lignin)) (PRN (-LRB- -LRB-) (NP (NN n.)) (-RRB- -RRB-))) (NP (NP (DT A) (NN substance)) (VP (VP (VBG characterizing) (NP (NN wood) (NNS cells))) (CC and) (VP (VBG differing) (PP (IN from) (NP (NP (NN cellulose)) (PP (IN in) (NP (PRP$ its) (NN conduct))))) (PP (IN with) (NP (JJ certain) (NN chemical) (NNS reagents)))))) (. .)))
Lignin ( n. ) A substance characterizing wood cells and differing from cellulose in its conduct with certain chemical reagents.
(ROOT (S (NP (NP (DT The) (NN action)) (PP (IN of) (S (VP (VBG burning) (NP (NP (DT a) (NN piece)) (PP (IN of) (NP (NN wood)))))))) (VP (VBZ forms) (NP (DT a) (JJ different) (NN chemical) (NN substance))) (. .)))