Iron

Question 1

what combines cytochromes, catalas, guanylate cyclase and MPO

Answer 1

hemoproteins

Question 2

What iron product is needed for mitochondrial respiration and TCA cycle?

Answer 2

iron sulfure cluster proteins

Question 3

Iron is a cofactor for what enzyme involved in serotonin synthesis

Answer 3

tyrosine hydroxylase

Question 4

Body Iron Components

Answer 4

Hemoglobin, Myoglobin, Enzymes, Transferrin, Ferritin and Hemosiderin

Question 5

Where is Fe absorbed?

Answer 5

duodenum-proximal small bowel

Question 6

What increases iron absorption?

Answer 6

gastric acid (Fe2+)

Question 7

What carries Fe across brush border?

Answer 7

heme carrier protein and hemopexin receptor (PCFT/HCP1)

Question 8

What enzyme releases iron from heme?

Answer 8

heme oxygenase

Question 9

2 oxidation states of Fe

Answer 9

2+ferrous and 3+ferric (non heme)

Question 10

Promoters of Iron absorptions

Answer 10

-ascorbic acid (FE3-> Fe2), citric acid, some spices, B carotene, alcohol

Question 11

Inhibitors of Irons absorption

Answer 11

phytic acid, polyphenols, tannins, calcium

Question 12

Transferrin

Answer 12

plasma iron transporter, made in liver, can bind 1-2 Fe3+, pH dependent, delivers Fe from macrophages and enterocytes to normoblasts in the bone marrow, binds Tfr1

Question 13

what reduces Fe3+ to Fe2+

Answer 13

STEAP

Question 14

what moves Fe2+ across the endosomal membrane into the cytoplasm

Answer 14

DMT1

Question 15

Storage of Fe

Answer 15

ferritin-IC

Question 16

What incorporates iron into protoporphyrin to form heme

Answer 16

ferrochelatase-mitochondrial protein important in erythroid precursors; final step in biosynthesis of heme

Question 17

what does hemoglobin bound by haptoglobin bind

Answer 17

CD163

Question 18

what takes up intravascular heme bound hemopexin

Answer 18

CD91

Question 19

conglomeration of ferritin molecules

Answer 19

hemosiderin

Question 20

transports Fe2+ across the cell membrane to the plasma

Answer 20

ferroportin

Question 21

GPI anchored ferrioxidase that converts Fe2+ to Fe3+ allowing for transferrin binding

Answer 21

ceruloplasmin

Question 22

keystone regulator of systemic iron homeostasis

Answer 22

hepcidin from HAMP gene

Question 23

binds to ferroportin and triggers its internalization and degradation in lysosomes–> decreases Fe from macrophages, hepatocytes and enterocytes, increased IC iron, get excess Fe in deficiency of this

Answer 23

action of hepcidin

Question 24

Is transcription increased or decreased of hepcidin with increased Fe

Answer 24

increased to increase transferrin saturation signals to hepatocytes to increase hepcidin expression via HFE and TfR2

Question 25

3 Storages of Fe

Answer 25

intracellular ferritin, serum ferritin, hemosiderin

Question 26

Most Fe stored in

Answer 26

hepatocytes (oral), RES macrophages (recycled) and bone marrow (recycled)