Question: what are four functions of the cell or plasma membrane
[{'answer': 'controls the movement of substances', 'provenance': [{'wikipedia_id': '33051527', 'title': 'Cell membrane', 'start_paragraph_id': 1, 'start_character': 796, 'end_paragraph_id': 1, 'end_character': 831, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'cell adhesion , ion conductivity and cell signalling'}, {'provenance': [{'wikipedia_id': '33051527', 'title': 'Cell membrane', 'start_paragraph_id': 1, 'start_character': 337, 'end_paragraph_id': 1, 'end_character': 1375, 'bleu_score': 0.6335613351459121, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4034704785039757219}, 'section': 'Section::::Abstract.'}]}]