Exam - Iron

Question 1

supplement label

Answer 1

helps prevent iron deficiency

Question 2

where is iron found

Answer 2

lots of foods at low levels - liver, meats, plant sources

Question 3

2 forms that iron can be found as in the body

Answer 3

heme (animals)
non-heme (plants)

Question 4

where is heme found

Answer 4

within porphyrin ring of hemoglobin and myoglobin

Question 5

what are the only 2 states of iron that are stable in the aqueous environment of the body and food:

Answer 5

ferric and serous

Question 6

functions of iron in the body

Answer 6

oxygen transport
redox reactions
iron metalloenzymes

Question 7

what are metalloenzymes

Answer 7

enzymes that need a metal ion as cofactor

Question 8

what percentage of iron ingested gets absorbed

Answer 8

10-18%

Question 9

2 fates of Fe2+ (ferrous)

Answer 9

either used in intestinal cells, stored in intestinal cells or transported to blood

Question 10

what are chelators

Answer 10

small organic compounds that form a complex with a metal ion

Question 11

what do chelators affect

Answer 11

iron absorption

Question 12

what happens if the iron-chelate is soluble

Answer 12

iron absorption is enhanced

Question 13

what happens if iron-chelate is insoluble

Answer 13

iron absorption is inhibited

Question 14

examples of enhancers

Answer 14

vitamin C (reducing agent)
pectin

Question 15

examples of inhibitors

Answer 15

polyphenols
oxalic acid
insoluble fibres

Question 16

what does coffee after a meal reduce

Answer 16

iron absorption by 50%

Question 17

how does oxalic acid inhibit

Answer 17

binds with iron, preventing its absorption

Question 18

how does iron get transported in the blood

Answer 18

in its ferric form, bound to transferrin

Question 19

why is it important that iron is bound to a carrier

Answer 19

unbound ferrous iron has a high redox activity and can readily lose an electron, increasing radical production

Question 20

what is ferritin

Answer 20

iron storage protein

Question 21

where is iron readily available from

Answer 21

ferritin

Question 22

what is hemosiderin

Answer 22

a complex of ferritins and denatured proteins found mostly in macrophages that engulfed red blood cells

Question 23

where is iron poorly available from

Answer 23

hemosiderin

Question 24

what is necessary for iron to attach to transferrin

Answer 24

oxidation of Fe2+ by ceruloplasmin

Question 25

examples of hemmed-dependent enzymes

Answer 25

catalase
thyroid peroxidase

Question 26

what does catalase do

Answer 26

converts H2O2 into H2O

Question 27

what does thyroid peroxidase do

Answer 27

addition of iodides to thyroglobulin protein

Question 28

4 groups where iron deficiencies are most seen

Answer 28

infants/young children
adolescents in early growth spurts
females during childbearing years
pregnant women

Question 29

general symptoms of iron deficiency

Answer 29

fatigue
pallor
weakness
hair loss/brittle nails
irritability
impaired immune system

Question 30

what percentage of people worldwide have iron deficiency

Answer 30

30%

Question 31

short term consequences of iron deficiency in fetal development/early childhood

Answer 31

lower test scores on mental development
lower test scores on motor development

Question 32

what does iron toxicity eventually cause

Answer 32

liver failure

Question 33

what is hemochromatosis

Answer 33

increased iron absorption

Question 34

what is hemosiderosis

Answer 34

iron deposition in tissues