L13- absorption of iron

Question 1

roles of iron in body

Answer 1

• transpors oxgyen and stores it
• involved in ETC
• plethera of enzymes
• control of cell cycle

Question 2

what condition does it lead to if there’s low amount of iron

Answer 2

IDA

Question 3

what condition does it lead to if there’s high amount of iron

Answer 3

hereditary haeochromatosis

Question 4

life cycle of the physiological processing of iron

Answer 4

iron consumed

• used to make RBCs in bone marrow
• once RBCs reach their lifetimes, they are engulfed by macrophages
• iron released into the blood

Question 5

what happens if theres too much iron in the body

Answer 5

it gets stored in the liver

Question 6

what happens if there’s too less iron in the body

Answer 6

iron released from liver

Question 7

types of dietary iron

Answer 7

inorganic and haem

Question 8

how does iron get taken up by the enterocyte

Answer 8

1. ferric ion reduced into Fe2+ by Dcytb
2. transported into cell by DMT 1
3. Fe2+ ion binds to ferritin so it becomes non toxic
4. transported out by FPN
5. Fe2+ into Fe3+ by hephaestin
6. Fe3+ get into a trnasferrin to be transported in the blood

Question 9

how does Fe-transferrin get taken up by non enterocyte

Answer 9

the cells have transferrin receptors on the surface on the cell so the Fe- transferrin bind to the receptors to get the iron

Question 10

major stores of iron

Answer 10

-liver, spleen, bone marrow

Question 11

what is hepcidin

Answer 11

hormone that regulates iron metabolsim

Question 12

what does hepcidin do to the levels of iron

Answer 12

stops the absorption of iron

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Question 13

if there’s high levels of iron absorbed, the hepcidin is what

Answer 13

hepcidin increases to stop the iron absorption

Question 14

if there’s low levels of iron absorbed, the hepcidin is what

Answer 14

hepcidin decreases to stimulate more iron absorption

Question 15

why is that when there’s inflammation due to a bacterial infection eg, hepcidin is released to stop absoprtion of iron

Answer 15

• bacteria need iron to proliferate
• so hepcidin stops it and locks the iron in the macrophages
• bacteria is then starved

Question 16

what’s chronic anaemia

Answer 16

anaemia caused by inflammation of diseases.

• this causes hepcidin to be released to lock the iron in
• even though there’s enough iron in the body, this results in anaemia due to the locking in

Question 17

why does hepcidin increase when obesity increase

Answer 17

the expression of hepcidin is increased

Question 18

what happens if you cant make hepcidin

Answer 18

-results in too much of iron
-there wont be enough ferritin to bind to the iron so cuases DNA and cell damage too
- leads to haeochromatosis
- causes organ damage in liver and pancreas
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Question 19

what’s IDA

Answer 19

• iron deficiency anaemia due to vegan diet and blood loss by menstrual cycle and GIT
• not enough iron in the body
• hepcidin is low and ferritin is low

Question 20

what’s coeliac disease

Answer 20

• Autoimmune disease of small bowel
• no villi on the surface of SI cells
• absorption doesnt occur

Question 21

what’s ulcerative disease

Answer 21

colon and rectum become inflamed

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