Control and absorption of iron

Question 1

What role does iron play in the human body?

Answer 1

Oxygen transport and storage
Electron transport
Enzymes
Cell cycle control

Question 2

How is iron excreted?

Answer 2

There is no active excretory mechanism

Question 3

What are the two classifications of dietary iron?

Answer 3

Inorganic

Haem

Question 4

What takes up iron?

Answer 4

DMT1

HCP1

Question 5

What enzyme makes iron absorbable?

Answer 5

Dcytb

Fe3+ to Fe2+

Question 6

What is ferritin?

Answer 6

Inert iron storage

Question 7

What is ferroportin?

Answer 7

The channel that exports iron from the cell

Question 8

What role does hephaestin play?

Answer 8

Hephaestin converts Fe2+ to Fe3+ bound to transferrin

Question 9

What is the role of HO-1?

Answer 9

Catalyses haem to release free iron and biliverdin

Question 10

What are the major stores of iron?

Answer 10

Liver
Spleen
Bone marrow

Question 11

How are iron levels communicated with the small bowel?

Answer 11

Hepcidin

Question 12

How does hepcidin work?

Answer 12

High iron levels stimulate hepcidin production in the liver

Hepcidin then inhibits take up of iron to lower iron levels

Question 13

How might hepcidin cause anaemia?

Answer 13

Hepcidin levels increased by inflammation or infection
Iron uptake reduced
Iron levels fall too much

Question 14

What is transferrin saturation?

Answer 14

The ratio of serum iron and total iron-binding capacity, multiplied by 100

Question 15

What is hereditary haemochromatosis?

Answer 15

Inability to produce hepcidin
Iron accumulates
Results in organ damage
1 in 300-400

Question 16

Describe iron deficiency anaemia

Answer 16

Most common nutritional disorder in the world

2 billion people

Question 17

How may coeliac disease affect iron absorption?

Answer 17

Autoimmune disorder of the small bowel
Inflammatory reaction causes villous atrophy
Iron deficient anaemia, weight loss and fatigue