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Flashcards in Iron in Disease Deck (115)
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1

What 2 things is iron essential for?

* Iron transport
* Electron transport

2

In iron, there is reversible/irreversible O2 binding from Hb

Reversible

3

Ferric

Fe3+

4

Ferrous

Fe2+

5

What 3 things is iron present in?

* Haemoglobin.
* Myoglobin.
* Enzymes e.g. cytochromes.

6

Why is iron dangerous?

Due to its chemical reactivity - oxidative stress

7

Because iron can be toxic to the body, what does the body do to prevent this?

* Safe transport.
* Safe storage.
* Regulation of iron absorption.

8

Iron does NOT have a ....

Mechanism of excretion

9

Iron does NOT have a mechanism of excretion

T

10

What is there in each globin chain?

1 haem group

11

What ion is found in each haem group of every globin chain?

Fe2+

12

Where does the Fe2+ ion in the haem group sit?

In the porphyrin ring

13

Where is the majority of body iron found?

In haem

14

How is haem formed?

Protoporphyrin is formed from porphobilinogen

This combines with Fe3+ to form haem.

15

Porphyrin ring + Fe2+ =

Haem

16

How much iron does the body absorb per day?

1mg / day

17

How much iron exists in:

i) plasma
ii) parenchymal tissues
iii) erythroid marrow
iv) red cell haemoglobin
v) macrophage stores?

i) 4mg
ii) 500mg
iii) 150mg
iv) 2500mg
v) 500mg

18

How much iron is lost per day?

1mg

19

Where does iron absorption occur?

In the duodenum

20

Iron absorption occurs in the _________

Duodenum

21

What is responsible for the transport of IRON INTO the DUODENAL ENTEROCYTE?

DMT (Divalent metal transporter) -1

22

What is the role of FERROPORTIN?

Facilitates iron EXPORT from the enterocyte

23

What happens to iron once it has been exported from he enterocyte?

It is passed on to transferrin for transport elsewhere

24

What is responsible for the down-regulation of ferroportin?

Hepcidin

25

What does hepcidin do?

Down-regulates ferroportin to decrease exportation of iron from the enterocyte

26

The regulation of iron absorption can be grouped into 3 factors, what are these?

1. Intra-luminal factors.
2. Mucosal factors.
3. Systemic factors.

27

What does intraluminal factors for regulation of iron absorption take into account?

* Solubility of inorganic iron.
* Haem iron is easier to absorb.
* The reduction of (Fe3+) to ferrous (Fe2+)

28

What does mucosal factors refer to?

The expression of iron transporters

29

Give examples of 2 iron transporters (used in the regulation of iron absorption).

* DMT-1 (divalent metal transporter) - at mucosal surface.
* Ferroportin - at serosal surface.

30

Where is ferroportin found?

At serosal surface