text: The most common region used in animal DNA barcoding is a stretch of 600 base pairs encoding asubunit of one of these proteins.
full_question: The most common region used in animal DNA barcoding is a stretch of 600 base pairs encoding asubunit of one of these proteins. After being released into the cytoplasm, one of these proteins binds toApaf-1, initiating the instrinsic apoptosis pathway. In phase I of drug metabolism, polar groups areintroduced to chemicals by the P450 oxidase type of these proteins. One of these proteins in the thylakoidmembrane transfers electrons between (*) photosystems II and I. One of these proteins gets reduced by theoxidation of coenzyme Q in Complex III, and four of them each transfer an electron to one oxygen molecule tomake water in Complex IV. For 10 points, name these heme-containing proteins whose "c" variety plays a key rolein the electron transport chain.
first_sentence: The most common region used in animal DNA barcoding is a stretch of 600 base pairs encoding asubunit of one of these proteins.
raw_answer: cytochromes [accept cytochrome c oxidase; accept cytochrome b6f; accept cytochrome bc1] 