( ( ( ( ( Each ( ( proton and ) neutron ) ) , ) ( in turn ) ) , ) ( ( consists ( of ( ( three ( smaller quarks ) ) ( ( bound together ) ( by ( ( other particles ) ( known ( as gluons ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT Each) (NN proton) (CC and) (NN neutron)) (, ,) (PP (IN in) (NP (NN turn))) (, ,)) (VP (VBZ consists) (PP (IN of) (NP (NP (CD three) (JJR smaller) (NNS quarks)) (VP (VBN bound) (PRT (RP together)) (PP (IN by) (NP (NP (JJ other) (NNS particles)) (VP (VBN known) (PP (IN as) (NP (NNS gluons)))))))))) (. .)))
Each proton and neutron, in turn, consists of three smaller quarks bound together by other particles known as gluons.
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (NP (CD three) (NNS quarks)) (PP (IN in) (NP (DT each) (NN proton) (CC and) (NN neutron))))) (. .)))