( ( That is ) ( , ( ( ( transmembrane proteins ) ( ( span ( from ( ( one side ) ( of ( a membrane ) ) ) ) ) ( through ( to ( ( the ( other side ) ) ( of ( the membrane ) ) ) ) ) ) ) . ) ) )
(ROOT (S (INTJ (DT That) (VBZ is)) (, ,) (S (NP (JJ transmembrane) (NNS proteins)) (VP (VBP span) (PP (IN from) (NP (NP (CD one) (NN side)) (PP (IN of) (NP (DT a) (NN membrane))))) (PP (IN through) (PP (TO to) (NP (NP (DT the) (JJ other) (NN side)) (PP (IN of) (NP (DT the) (NN membrane)))))))) (. .)))
That is, transmembrane proteins span from one side of a membrane through to the other side of the membrane.
(ROOT (S (NP (JJ Transmembrane) (NNS proteins)) (VP (VBP span) (NP (DT the) (JJ entire) (NN plasma) (NN membrane))) (. .)))