Iron Use and Cycle Flashcards
Which form of Iron is absorbed? How is it transported into enterocyte?
Ferrous (2+), via DMT1 (divalent metal transporter)
What are the two sources of iron coming into enterocyte?
Iron from food we eat and free iron coming in as heme molecule
This molecule stores excess mineral iron and has an outside protein coat
Ferritin (ferr, tin = a tin to store iron)
This green bile pigment is a result from the breakdown of heme of hemoglobin in erythrocytes
Biliverdin
This molecule transports iron out of cell
Ferroportin
After leaving the enterocyte via ferroportin, ferrous iron gets converts to ferric form via this protein
Hephaestin
The name of this transport glycoprotein when not bound to iron
Apo-transferrin
Transport protein when bound with 2 irons
Transferrin
What is every cell using heme for?
Electron transport chain! Every ETC protein has heme in them. Used to transport electrons
Endocytosis of transferrin relies on this receptor in which type of cell?
TfR (Transferrin receptor), in erythroblast
What state of iron binds to transferrin?
Ferric state (3+), two irons per transferrin
What happens to transferrin after endocytosis in erythroblast?
Tranferrin molecule gets released via TfR, and now called “Apotransferrin” gets reused
Once transferrin binds to TfR receptor on erythroblast, how does it enter cell?
Endocytosis
Once in erythroblast, Fe3+ gets converted to Fe2+ and is mainly used to make
Makes heme for hemoglobin
Why does macrophage need iron?
serves as internal storage of extra iron for body
What are macrophage’s two sources of iron?
Engulfing RBCs (that contain iron in heme to make up hemoglobin), and uptake of transferrin via TfR
If other parts of body need iron, iron leaves the macrophage via this transporter
ferroportin