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Flashcards in Iron Deck (31)
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1

what forms of iron are stable in the body

1. oxidized ferric
2. reduced ferrous

2

where and by what is iron absorbed

basolateral membrane by ferroportin

3

heme remains absorbed across the brush boarder by

heme carrier protein 1

4

heme is hydrolyzed by enzyme _____ into ____ and ______

heme oxygenase
ferrous iron
protoporphyrin

5

nonheme iron hydrolyzed from food by ____ and ___ (released as ferric iron)

proteases
HCL

6

what is found at the brush border to reduce oxidized ferric to reduced ferrous

duodenal cytochrome b reductase

7

what transports iron, calcium, zinc, and copper throughout the cell

mobilferrin

8

what membrane transport protein does the basolateral boarder use

ferroportin (FPN1)

9

ferrous iron transported through basolateral boarder by copper containing protein called

hephaestin

10

what is the glycoprotein made in the liver that carries 2 iron atoms called

transferrin

11

what is the body's iron storage protein called

ferritin

12

what are the two isoforms of tranferrin receptors

1. TfR1 - cell membranes
2. TfR2 - liver and intestinal cell membranes

13

what are the 3 routes macrophages can acquire iron

1. phagocytosis of RBC's
2. receptor mediated endocytosis of hemoglobin
3. receptor mediated endocytosis of transferrin

14

what is the primary storage from of iron

ferritin

15

long term storage protein (thought to be degradation product of ferritin)

hemosiderin

16

ferritin levels in the liver drive production of ____ (suppresses iron absorption)

hepcidin

17

fully saturated with 4 iron molecules when cellular iron concentrations are high

iron response element binding protein (IRE-BP)

18

iron response element binding protein (IRE-BP) binds to what cytosolic enzyme

aconitase

19

mitochondrial enzyme involved in last step of heme synthesis

ferrochelatase

20

____ for serotonin synthesis

tryptophan hydroxylase

21

____ for tyrosine synthesis

phenylalanine hydroxylase

22

_____ for dopamine synthesis

tyrosine hydroxylase

23

what two dioxygenases does collagen synthesis require

1. prolyl hydroxylase
2. lysyl hydroxylase

24

what two dioxygenases does carnitine synthesis require

1. trimethyllysine dioxygenase
2. 4 - butyrobetaine dioxygenase

25

iron as a pro-oxidant

fenton reaction

26

_____ enhances iron absorption

vitamin c

27

copper is a cofactor for what two ferroxidase ezymes

1. hephaestin
2. ceruloplasmin

28

iron cannot be mobilized out of small intestine without ___ bc it would lead to ___

copper
anemia

29

__ can cause anemia

lead

30

_____ can insert lead instead of iron into center of heme ring

ferrochelatase (inhibits aminolevulinic acid dehydrase)