Summary biochemistry of folic acid and vitamin B12
5 views 0 purchase
Course
Biochemistry
Institution
Biochemistry
Introduction:
Folic acid and vitamin B12, two water-soluble vitamins, are integral components of human nutrition, playing crucial roles in various biochemical pathways essential for cellular health and function. Their interdependent relationship underscores the complexity of one-carbon metabolis...
Biochemistry: folic acid & B12
Vitamins → water soluble → B complex → (folic acid & B12)
Nutritional anemias → Macrocytic low MCV → deficiency in B12 and folate B9
Folic acid (also known as B9 or pteroyl-glutamic acid))
Folate, the anion of folic acid,
made up of three different components:
1. Pteridine derivative.
2. 4-aminobenzoate PABA
(contain carboxyl groups→ responsible for the acidity of folate)
3. One or more glutamate residues. (R) (amino acid)
Plays a key role in one-carbon metabolism.
Essential for the biosynthesis of several compounds.
Most common deficiency in the USA in women(pregnancy) and
alcoholics
Folic acid is a light-sensitive molecule
(due to the presence of the rings in its structure)
active form of folic acid:
tetrahydrofolate (THF)
Have different structures that differ
due to functional groups' variety
we are unable to synthesize folic acid (we lack specific enzymes),
we *depend on normal flora to do primary steps and then converted
to its active form in the liver
*or consumed by food (green vegetables)
absorbed by the upper part of the(( jejunum))
transported in the blood by Beta globins → Liver conversion to the
co-enzyme
*Not stored in tissues
*sulfonamide competitively inhibits the synthesis of folic acid in
microorganisms and → thereby decreases the synthesis of nucleotides
needed for the replication of DNA
*Dihydrofolate reductase is competitively inhibited by methotrexate, a folic
acid analogue
NADH + H+ NADP+ NADH + H+ NADP+
Dihydrofolate Dihydrofolate
Reductase reductase
Diet folic acid dihydrofolic THF
Acid
X X
Methotrexate Methotrexate
Methotrexate → X synthesis of DNA → used to treat psoriasis, rheumatoid
arthritis, and neoplastic diseases
Cancer cells might become resistant to methotrexate, by duplicating the
gene of the enzyme itself
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller miloo4. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R64,83. You're not tied to anything after your purchase.
