( Digestion ( typically ( ( ( ( ( ( begins ( in ( the stomach ) ) ) ( when ( pepsinogen ( is ( converted ( to ( pepsin ( by ( ( the action ) ( of ( hydrochloric acid ) ) ) ) ) ) ) ) ) ) ) , ) and ) ( ( continued ( by ( ( trypsin and ) chymotrypsin ) ) ) ( in ( the ( small intestine ) ) ) ) ) . ) ) )
(ROOT (S (NP (NNP Digestion)) (ADVP (RB typically)) (VP (VP (VBZ begins) (PP (IN in) (NP (DT the) (NN stomach))) (SBAR (WHADVP (WRB when)) (S (NP (NN pepsinogen)) (VP (VBZ is) (VP (VBN converted) (S (VP (TO to) (VP (VB pepsin) (PP (IN by) (NP (NP (DT the) (NN action)) (PP (IN of) (NP (JJ hydrochloric) (NN acid))))))))))))) (, ,) (CC and) (VP (VBD continued) (PP (IN by) (NP (NN trypsin) (CC and) (NN chymotrypsin))) (PP (IN in) (NP (DT the) (JJ small) (NN intestine))))) (. .)))
Digestion typically begins in the stomach when pepsinogen is converted to pepsin by the action of hydrochloric acid, and continued by trypsin and chymotrypsin in the small intestine.
(ROOT (S (NP (DT The) (JJ small) (NN intestine)) (VP (VBZ begins) (PP (IN in) (NP (DT the) (NN stomach)))) (. .)))