Iron Metabolism And Microcytic Anaemia

Question 1

T
A
I
L
S

Answer 1

Thalassaemia
Anaemia of chronic disease
Iron deficiency
Lead poisoning
Sidero-blastic anaemia

Question 2

Iron uses

Answer 2

Haemoglobin, myoglobin

Cofactors In enzymes
Eg. Cytochromes, oxidative phosphorylation
Krebs cycle enzymes

Question 3

Ferrous vs ferric

Answer 3

Fe2+ vs fe 3+
Dietary iron comes as ferrous and as a mixture

Question 4

Iron intake

Answer 4

Reductase turns Fe3+ to Fe 2+ (easy because acidic)
Then fe2+ absorbed into cell through DMT1 transporter
Can be stored and is turned into fe3+ for that
Else ferroportin transports ferrous iron into blood, ferroportin can be inhibited by hepcidin.
Then Hephaestin oxidised it to fe3+ and transferrin transports it in blood

Question 5

Factors affecting absorbtiom of non haem iron (Fe3+)

Answer 5

-ve
Tannins
Fibre
Antacids

+ve
Vit C (required for reduction to ferrous iron. Also helps prevent formation of insoluble iron compounds)

Question 6

Functional vs stored iron

Answer 6

Total~ 3350mg
Functional- 2000 haemoglobin
330 myoglobin
50 enzymes
3 transported by transferrin
and stored -1000
Ferritin - protein complex
Haemosiderin- aggregates of clumped ferritin, denatured proteins and lipid. Accumulates in macrophages in liver mostly, not good

Question 7

Cellular uptake of iron

Answer 7

Transferrin binds to transferrin receptor, endocytosis
Fe3+ released and reduced by acidic micro environment.
DMT1 transports fe2+ to cytosol.
Fe2+ can them be transported into blood via FPN1, or stored in ferritin, or used in mitochondria ( via MFRN)