Biochemistry 3070 Vitamins: Biochemical Roles Vitamins Vitamins are necessary components of healthy diets and play important roles in cellular metabolism. Vitamins are considered “micronutrients.”
B1, B2, B3, B6, B12
were removed from the list of essential vitamins.
Structures of Water-soluble Vitamins
The most recognized of all vitamins is Vitamin C (ascorbic acid):
Formation of 4-hydroxyproline:
“Some did lose all their strength, and could not stand on their feet… Others also had all their skins spotted with spots of blood of a purple colour: then did it ascend up to their ankles, knees, thighs, shoulders, arms, and necks. Their mouths became stinking, their gums so rotten, that all the flesh did fall off, even to the roots of the teeth, which did also almost all fall out.
- Jacques Cartier, 1536
The fat-soluble vitamins share some structural and solubility similarities.
Note: There is an major error in this table. What is it?
The function and deficiency of A and E are switched.
Vitamin A – Our visual pigment:
2% - 1 color pigment gene
20% - 2 color pigment genes
50% - 3 color pigment genes
20% - 4 color pigment genes
5% - 5 color pigment genes
Vitamin D acts as a hormone, helping regulate the uptake of calcium from the intestines by promoting the synthesis of calcium-binding protein in the mucosal cells.
Deficiency of this vitamin causes “rickets,” a condition of low levels of calcium, which results in soft and pliable bones, leading to bending and distortion.
Credits: Many of the diagrams used in these slides were taken from Stryer, et.al, Biochemistry, 5th Ed., Freeman Press (in our course textbook) and from prior editions of this text.