( These ( ( are ( molecules ( which ( ( ( are ( produced ( at ( ( the end ) ( of ( one ( nerve cell ) ) ) ) ) ) ) and ) ( ( ( ( diffuse across ) ( a gap ) ) ( to ( ( the ( opposite end ) ) ( of ( a ( second ( nerve cell ) ) ) ) ) ) ) ( so ( as ( to ( ( cause ( the ( second cell ) ) ) ( to ( ( transmit ( an ( electrical signal ) ) ) ( down ( its length ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT These)) (VP (VBP are) (NP (NP (NNS molecules)) (SBAR (WHNP (WDT which)) (S (VP (VP (VBP are) (VP (VBN produced) (PP (IN at) (NP (NP (DT the) (NN end)) (PP (IN of) (NP (CD one) (NN nerve) (NN cell))))))) (CC and) (VP (VBD diffuse) (PRT (RP across)) (NP (DT a) (NN gap)) (PP (TO to) (NP (NP (DT the) (JJ opposite) (NN end)) (PP (IN of) (NP (DT a) (JJ second) (NN nerve) (NN cell))))) (ADVP (RB so) (RB as) (S (VP (TO to) (VP (VB cause) (NP (DT the) (JJ second) (NN cell)) (S (VP (TO to) (VP (VB transmit) (NP (DT an) (JJ electrical) (NN signal)) (PP (IN down) (NP (PRP$ its) (NN length)))))))))))))))) (. .)))
These are molecules which are produced at the end of one nerve cell and diffuse across a gap to the opposite end of a second nerve cell so as to cause the second cell to transmit an electrical signal down its length.
(ROOT (S (NP (NP (DT An) (JJ electrical) (NN signal)) (PP (IN along) (NP (DT a) (NN nerve) (NN cell)))) (VP (VBZ triggers) (NP (NP (DT the) (NN secretion)) (PP (IN of) (NP (NN neurotransmitter) (NNS molecules))))) (. .)))