Iron revision - week 12

Question 1

Absorbed

Answer 1

Non heme iron(Fe3+, ferric) requires ferriductase to reduce to fe2+ (ferrous). It is than transported across membrane by DMT1. It is then stored by ferritin. Ferriportin is required to let hephaestin into blood

Question 2

Transported

Answer 2

As Fe3+ bound to transferrin
Ferroxidase enzymes
– Hephaestin in enterocytes and ceruloplasmin in blood convert Fe2+ to Fe3+
– In tissue cells – uptake by endocytosis – lysosomes relase iron and transferrin is recycled

Question 3

Stored

Answer 3

Ferritin
- binds and stored iron inenterocytes
- prevents excess absorption (mucousal block)
ferroportin
- transport iron out of enterocytes when supplies are low for release to blood

in liver, bone marrow, spleen, bound to ferritin or hemosiderin

Question 4

Excreted

Answer 4

o 10% via bile and faeces

o 90% recycled

Question 5

Major function

Answer 5

o	Functional component of hemoglobin and other key comounds used in respiration, immune function, cognitive development and energy metabolism
o	Hemoglobin (transport of O2 and Co2)
o	Myoglobin (transport of O2
o	Oxidation – reduction reactions

Question 6

Food source

Answer 6

Meats, seafood, eggs, fortified cereals

Question 7

Outcome of deficiency with related mechanism

Answer 7

iron-deficiency anemia = microcytic hypochromic anemia

Question 8

Toxicity

Answer 8

Upset GIT