Vitamin Deficiency Flashcards
1
Q
riboflavin deficiency
A
- rare in the United States but can be seen in chronic alcoholics and the severely malnourished.
- Clinical manifestations include angular stomatitis, cheilitis, glossitis, seborrheic dermatitis, eye changes (eg, keratitis, corneal neovascularization), and
anemia. - riboflavin (vitamin B2)-containing coenzymes are key constituents of the electron transport chain.
- first phosphorylated to become flavin mononucleotide (FMN), which can then be integrated into a coenzyme-flavin complex or further phosphorylated to flavin adenine dinucleotide (FAD).
- FMN and FAD participate as coenzymes in numerous redox rxns and are converted into reduced, energy-carrying states (FMNH2 and FADH2) through the acceptance of electrons
FMN serves are component of complex 1
FAD functions as component of succinate dehydrogenase (complex II)
Complex II participates in both ETC and TCA cycle.
During TCA cycle, succinate dehydrogenase converts succinate to fumarate and transfers electrons to coQ (ubiquinone) via FAD
Complex II also accepts electrons from other sources of FADH2 such as fatty acid oxidation
