Flashcards : Folate and B12 Metabolism Essentials — 16 cartes

DNA synthesis, methylation, RBC formation

DNA synthesis, methylation, neurological function

Leafy vegetables, beans, fruits, yeast, mushrooms, animal meat

Animal products: liver, milk, fish, eggs; microbial synthesis

Pteroylmonoglutamate with pteridine, p-aminobenzoic acid, glutamate residues

Corrin ring with central cobalt ion

Jejunum after conversion to monoglutamate by conjugase

Ileum, requires intrinsic factor for uptake

Converted to monoglutamate, transported via PCFT transporter

Bound to intrinsic factor, absorbed via receptor-mediated endocytosis in ileum

Transfers methyl groups, supports DNA synthesis and methylation

Methionine synthase, uses methylcobalamin to convert homocysteine to methionine

Megaloblastic anemia, neurological deficits, neural tube defects

Serum folate, serum B12, methylmalonic acid, homocysteine

Both needed for methylation; B12 deficiency causes folate trap, masking deficiency

Megalo-blastic anemia, neural tube defects, impaired DNA synthesis