( These ( ( are ( ( membrane-enclosed pockets ) ( within ( a cell ) ) ) ) . ) )
(ROOT (S (NP (DT These)) (VP (VBP are) (NP (NP (JJ membrane-enclosed) (NNS pockets)) (PP (IN within) (NP (DT a) (NN cell))))) (. .)))
These are membrane-enclosed pockets within a cell.
(ROOT (S (NP (DT A) (NN plasma) (NN membrane)) (VP (VBZ encloses) (NP (NP (DT the) (NN border)) (PP (IN of) (NP (NN animal) (NNS cells))))) (. .)))