alleryStart learning →Which two components make up complex I of the electron transport chain?
ACytochrome b together with cytochrome c
BHeme groups and a pair of copper ions
CPlastoquinone and plastocyanin carriers
DFlavin mononucleotide and an iron-sulfur protein
Answer & Solution
Correct answer: D. Flavin mononucleotide and an iron-sulfur protein
1. Two electrons are carried to the first complex aboard NADH.
2. That complex is composed of flavin mononucleotide and an iron-sulfur containing protein.
3. Flavin mononucleotide is derived from vitamin B2, riboflavin, and acts as a prosthetic group.
4. Cytochrome b belongs to the third complex, so that pairing points to the wrong place in the chain.
5. Heme groups and copper ions are the hallmark of the fourth complex, where oxygen is held.
6. Plastoquinone and plastocyanin are carriers of the chloroplast chain, not the mitochondrial one.
_Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 7 "Cellular Respiration", section 7.4 Oxidative Phosphorylation_
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