This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: ETC, Subject name: Biochemistry
Which is the only non-protein member of ETC ? 
Select and explain. 
A. Cytochrome c, B. CoQ, C. Complex V, D. Complex II
B: CoQ
Answer: B: CoQ 
Explanation: ETC has: five protein complexes- Complex I to V two mobile electron carriers - Co Q/ubiquinone and cyt c All complexes and cytochrome c are proteins except CoQ Coenzyme Q not a protein. hydrophobic, lipophilic compound made up of isoprene units, present within the inner mitochondrial membrane. anti-oxidant Cytochrome c is the only member of ETC, not lying in IMM