<prompt> Flavoproteins are component of which complex of respiratory chain:Complex IComplex IIBoth of the aboveNone of the above  <response>: Flavoproteins are impoant components of Complexes I and II. The oxidized flavin nucleotide FMN or FAD can be reduced in reactions involving the transfer of two electrons to form FMNH2 or FADH2, but they can also accept one electron to form the semiquinone. Ref: Harper 28th edition, chapter 13. 