Question: where do krebs (step 2) and the etc (step 3) occur
[{'answer': 'mitochondrial matrix', 'provenance': [{'wikipedia_id': '92236', 'title': 'Electron transport chain', 'start_paragraph_id': 12, 'start_character': 96, 'end_paragraph_id': 12, 'end_character': 116, 'bleu_score': 1.0, 'section': 'Section::::In mitochondria.:Mitochondrial redox carriers.\n'}]}, {'provenance': [{'wikipedia_id': '92236', 'title': 'Electron transport chain', 'start_paragraph_id': 12, 'start_character': 0, 'end_paragraph_id': 12, 'end_character': 1074, 'bleu_score': 0.9876155018005031, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2142576714619334384}, 'section': 'Section::::In mitochondria.:Mitochondrial redox carriers.\n'}]}]