lecture 11: riboflavin and thiamin

Question 1

riboflavin (vitamin B2)

Answer 1

required for a variety of metabolic functions including FA oxidation, ETC, DNA replication/repair, etc

Question 2

2 physiological flavo-coenzymes derived from riboflavin

Answer 2

FMN (phosphorylated form) and FAD (synthesized from FMN by addition of AMP)

most flavin coenzymes are non-covalently associated

Question 3

isoalloxazine ring of FAD and FMN

Answer 3

considered the most chemically versatile redox cofactor in the cell
1 or 2 electron transfers
can lead to formation of double bonds, removal of double bonds or amine groups, and hydroxylation of aromatic molecules

Question 4

cytochrome P450

Answer 4

functions in the metabolism of cholesterol, xenobiotics, drugs, steroids, prostaglandins, vitamins A and D

Question 5

semiquinone state

Answer 5

capable of accepting and donating single electron - intermediate oxidative state

isoalloxazine ring

Question 6

riboflavin deficiency

Answer 6

resembles niacin deficiency

stunted growth, skin lesions

Question 7

food sources of riboflavin

Answer 7

we cannot produce but we can store and consume - no de novo synthesis pathway
mainly in coenzymatic forms, typically as FAD
meets and greens

Question 8

thiamin diphosphate

Answer 8

two phosphates are attached to hydroxyl group of thiamin to make thiamin diphosphate, active form of cofactor

Question 8

thiamin deficiency

Answer 8

beriberi
fast heart rate, SOB, numbness, etc
component of rice hulls could reverse disease

Question 10

decarboxylation

Answer 10

thiamin is essential to the pyruvate dehydrogenase complex (link btw glycolysis and CAC)