( ( ( ( ( ( Integral ( membrane proteins ) ) ( function ( when ( incorporated ( into ( a ( lipid bilayer ) ) ) ) ) ) ) , ) and ) ( they ( are ( ( held ( tightly ( to ( lipid bilayer ) ) ) ) ( with ( ( the help ) ( of ( an ( annular ( lipid shell ) ) ) ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (JJ Integral) (NN membrane) (NNS proteins)) (VP (VBP function) (SBAR (WHADVP (WRB when)) (S (VP (VBN incorporated) (PP (IN into) (NP (DT a) (NN lipid) (NN bilayer)))))))) (, ,) (CC and) (S (NP (PRP they)) (VP (VBP are) (VP (VBN held) (ADVP (RB tightly) (PP (TO to) (NP (NN lipid) (NN bilayer)))) (PP (IN with) (NP (NP (DT the) (NN help)) (PP (IN of) (NP (DT an) (NN annular) (NN lipid) (NN shell)))))))) (. .)))
Integral membrane proteins function when incorporated into a lipid bilayer, and they are held tightly to lipid bilayer with the help of an annular lipid shell.
(ROOT (S (NP (JJ Integral) (NNS proteins)) (VP (VBP are) (VP (VBN embedded) (PP (IN in) (NP (JJ libid) (NN bilayer))))) (. .)))