Flashcards in Zinc Deck (34)
Moves zinc out of cells.
*** ZIP14 ***
Out of blood into liver
Located on hepatocytes, upregulated during infection.
Removes zinc from blood and away from infective organisms that can use it.
Up regulation can indicate infection.
Inversely related to zinc status.
Zinc absorption low = more ZIP4 (enhances absorption)
Mutation causes malabsorption syndrome.
Transfer to enterocyte
Can reabsorb zinc back into enterocyte.
Reabsorbs zinc if there's too much in circulation.
Sloughs off cells to get rid of zinc.
*** ZnT6 ***
Transfer to lumen
Recycles zinc from enterocyte to the lumen to be excreted. Active.
*** ZnT1 ***
Out of cells into blood
Transports zinc out of cells.
Moves zinc into cells.
Red meats, oysters, fortified cereals.
Supplementation on empty stomach.
8 mg women
Double for vegetarians (decreased bioavailability in plant foods due to non heme iron)
Higher absorption probably (low zinc status)
Component of ~200 metalloenzymes.
Structural integrity more so than functional.
Binds to AA at catalytic sites.
Solid, stable structure for proteins. Many functions.
Can curl along DNA strands to read DNA sequences.
*** Metalloenzyme component: Ligase and Lyase ***
Catalyzes the joining of 2 large molecules.
Catalyzes the breaking of various bonds.
Zinc in development/ growth
Regulates gene expression and cell replication.
Can result in poor growth in children if deficient because cells don't grow fast enough.
Retardation and skeletal growth impaired.
Zinc and infections
Structural role in hormones (thymulin - immunity)
Retionol to retinal conversion (RBP synthesis retinonol binding protein)
Zinc and taste
Zinc required for gustin synthesis.
Gustin is zinc-containing protein in saliva.
Growth retardation, skeletal abnormalities, and delayed sexual maturation in children. Zn used in cell division and DNA replication.
Infection (thymulin and retinal conversion)
Skin lesions (cell growth)
Loss of taste (hypogeusia) [gustin]
UL 40mg/ day
Also creates copper deficiency (zinc binds to metallothionine better than copper)
Protein carriers that transfer zinc through blood
Transferrin, immunoglobulin, and the AA's cysteine and histidine.
Metallothionine stores zinc in tissues.
Liver stores zinc when it's not being transferred.
Albumin contains 60% of Zn in blood
Acids: low pH, HCl, citric acid, AA.
Zinc is usually bound to proteins, which acids break away.
Non heme iron, calcium, antacids, tannins, phytates, oxalate.
Excrete zinc instead of absorb.
Upregulated when zinc levels are high.
Binds to zinc to form metallothionine.
Zinc dependent protein used for taste
Transferred through the blood bound to protein carriers:
Albumin, Transferrin, Immunoglobulins, etc.
AA: histidine and cysteine
Transport to tissue cells
Brings zinc out of blood into cell.
Can either be stored, used as a cofactor, or ego to nucleus to upregulate thionine to bind to something.
Directly correlated to Zn status. Bind to Zn.
More Zn = more metallothionine
How can zinc be recycled?
Should be taken on empty stomach.