Question: where does a substrate attach to an enzyme
[{'answer': 'the active site', 'provenance': [{'wikipedia_id': '188688', 'title': 'Active site', 'start_paragraph_id': 1, 'start_character': 12, 'end_paragraph_id': 1, 'end_character': 27, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '188688', 'title': 'Active site', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 668, 'bleu_score': 0.9509503382229441, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15632758299029619460}, 'section': 'Section::::Abstract.'}]}]