Minerals

Question 1

transferrin

Answer 1

transports iron in the blood between the intestine, RES, and bone marrow

Question 2

ferritin and hemosiderin

Answer 2

storage forms of iron, found in the liver and RES

Question 3

two forms of injested iron

Answer 3

heme and non-heme

Question 4

which form of iron is more bioavailiable?

Answer 4

heme iron

Question 5

How is heme iron absorbed?

Answer 5

remains bound to heme, transported by Heme carrier protein 1 in the duodenum and jejunum, binds to ferritin in the enterocyte

Question 6

How is non-heme iron absorbed?

Answer 6

it is first reduced to the 2+ form by Dcytb and then transported to the enterocyte by DMT1

Question 7

duodenal cytochrome B

Answer 7

reduces heme from 3+ to 2+ in the intestines

Question 8

DMT1

Answer 8

transports Fe2+ into the enterocyte

Question 9

ferric hydroxide

Answer 9

complexes with iron to prevents its absorption

Question 10

factors that enhance non-heme absorption

Answer 10

acids (help solubilize), chelation by organic molecules, upregulation of DMT1 because of deficiency

Question 11

factors that impair iron absorption

Answer 11

polyphenols, oxalic acid, phytates, phosphorylated serine, calcium, phosphate, zinc, magnesium, nickel

Question 12

ferroportin 1

Answer 12

transports iron out of the enterocyte and into the blood

Question 13

hephaestin

Answer 13

oxidized iron to Fe3+ form

Question 14

how does iron get exported to the circulation

Answer 14

It leaves the cell through ferroportin and then gets oxidized to Fe3+ by hephaestin, and finally it binds to transferrin

Question 15

transferrin receptor

Answer 15

binds circulating transferrin and iron is taken up into the cell

Question 16

most common deficinecy worldwide is

Answer 16

iron

Question 17

hepcidin

Answer 17

regulates iron efflux into circulation from intestine, liver, spleen and lymph nodes

Question 18

how is iron absorption regulated by hepcidin

Answer 18

when hepcidin levels increase, iron is stored in the body and when levels decrease, iron is released. This occurs due to the expression of ferroportin on the basolateral membranes of enterocytes

Question 19

glossitis and angular stomatitis

Answer 19

red tongue and lips from an iron deficiency

Question 20

koilonychia

Answer 20

bending of the nails from iron deficiency

Question 21

hereditary hemochromatosis

Answer 21

defect in hepcidin, results in too much iron in the blood, treated by bleeding

Question 22

risk factors of copper deficiency

Answer 22

upper gastrointestinal surgery, zinc supplements, malabsorption, Menke’s Celiac

Question 23

Manifestations of copper deficiency

Answer 23

neurologic (peripheral neuropathy), hematologic, iron deficiency

Question 24

Wilson’s disease

Answer 24

copper overload due to mutations in the copper ATPase leading to copper accumulation in the liver

Question 25

Menke’s disease

Answer 25

mutation in copper transporter, results in copper deficiency

Question 26

metallothionein

Answer 26

binds both copper and zinc in the enterocyte but has a higher affinity for copper, when there is too much zinc in the diet, MT is overexpressed resulting in a copper deficiency

Question 27

vitamin C and iron

Answer 27

VC helps keep iron in its reduced form and increases absorption

Question 28

transporters of copper

Answer 28

DMT1 and Crt

Question 29

copper deficiency is similar to a deficiency in

Answer 29

vitamin B12

Question 30

transporters of zinc

Answer 30

DMT1 and ZIP4