( ( ( Antibodies Proteins ) ( in ( ( the ( immune system ) ) ( that ( recognize ( ( antigens and ) help ) ) ) ) ) ) ( ( kill ( invading microorganisms ) ) . ) )
(ROOT (S (NP (NP (NNP Antibodies) (NNPS Proteins)) (PP (IN in) (NP (NP (DT the) (JJ immune) (NN system)) (SBAR (WHNP (WDT that)) (S (VP (VBP recognize) (NP (NNS antigens) (CC and) (NN help)))))))) (VP (VBP kill) (S (VP (VBG invading) (NP (NNS microorganisms))))) (. .)))
Antibodies Proteins in the immune system that recognize antigens and help kill invading microorganisms.
(ROOT (S (NP (NNS Antibodies)) (VP (VBP recognize) (CC and) (VBP combine) (PP (IN with) (NP (JJ harmful) (NNS materials))) (, ,) (PP (VBG including) (NP (NP (DT both) (JJ toxic) (NNS chemicals)) (CC and) (NP (JJ invasive) (NNS microorganisms))))) (. .)))