Iron Flashcards
Is Ferrous iron Fe+2 or Fe+3?
Fe+2
Which is the correct way: Fe+2 or Fe2+?
Both are correct
Is Ferric iron Fe+2 or Fe+3?
Fe+3
how can you remember that Ferrous iron is Fe+2?
Ferrous is like a Ferris wheel
At what pH is Fe(OH)3 most soluble in water?
pH 8
what food sources contain heme iron?
meat, fish, poultry, oysters, clams
what food sources contain non-heme iron?
nuts, fruits, veggies, grains, tofu, dairy
what grain foods are fortified with nonheme iron?
breads, rolls, pasta, cereals, flour
which forms of iron are approved for food fortification? (multiple answers)
a. Ferrous citrate
b. Ferrous fumarate
c. Ferrous gluconate
d. Ferric citrate
e. Ferric monohydrate
b. Ferrous fumarate
c. Ferrous gluconate
d. Ferric citrate
T/F heme iron is a metalloporphyrin
true
define a metalloporphyrin
porphyrin referring to numerous pyrrole rings surrounding a metal structure
when referring to “heme” iron, what does that mean?
iron contained within the poryphyrin structure
what are the main roles iron plays in the body? (three things)
oxygen transport
drug metabolism
electron transport
for animal protein, what enzyme cleaves the globin to allow heme to be transported into the intestine cell?
HCl protease
which transporter allows heme to enter the intestine cell?
hcp1
for plant protein, nonheme iron is broken down and transported into the cell as Fe2+ by what transporter?
DMT1
for plant protein, how is Fe3+ taken into the cell?
it is either converted into Fe2+ by dcytb reductase or binds with a ligand to go through the integrin transporter
what enzyme converts Fe3+ into Fe2+ allowing it to enter the cell?
Dcytb reductase
T/F if Fe3+ enters the cell via integrin transporter, it is reduced into Fe2+ inside the cell
True
what is the name of the transporter that transports Fe2+ to the body from the intestine cell?
Ferroportin
what does heme oxygenase do?
opens heme ring
T/F DMT1 allows transport of any metal with a 2+ charge
True
what does heme oxygenase convert heme into if it is to be transported? (three products)
billiverdin, ferrous iron, and carbon monoxide
iron binds to what ligand for transport through the membrane? (to portal blood)
mobilferrin
what oxidizes iron after it transports Fe2+ out of the cell, allowing it to attach to transferrin for transport in the blood?
hephaestin
***watch the lecture to learn the concept of iron going in and out of the cell
.
T/F Fe(OH)3 is relatively soluble
False, insoluble
which form of iron is mainly released into the small intestine? (ferric or ferrous)
ferric
T/F Fe2+ is fairly soluble
True
why must ferric iron bind to ligands in order to be soluble enough to enter cell? (think of pH)
ferric iron pH is greater than 7 making it relatively insoluble, ligands increase solubility
Which of these compounds enhance iron absorption? (multiple answers) a. grapefruit juice b. ascorbic acid c. whole grains d. sugar e. citric acid f. lactic acid g, tartaric acid h. mucin
b,d,e,f,g,h
how does ascorbic acid enhance iron absorption?
can reduce Fe3+ to Fe2+ which can form a complex with ascorbate increasing irons bioavailability
which of these compounds inhibits iron absorption? (multiple answers)
a. grapefruit juice
b. tannic acid
c. pyruvic acid
d. ellagic acid
e. chlorogenic acid
f. streubic acid
g. epigallocatechin gallate
h. monocytochloric mallate
i. oxalic acid
j. phytates
k. phosvitin
b,d,e,g,i,j,k
which of these metals/minerals are inhibitors of iron? (multiple answers)
a. Magnesium
b. Calcium
c. Basalt
d. Zinc
e. Aluminum
f. Manganese
g. Nickel
h. Alunogen
b,d,f,g
How can Ca2+, Zn 2+, Mn2+, and Ni2+ cause decrease in iron absorption? (think of the transport into the cell)
They all compete with the DMT1 transporter
iron is transported in your blood circulation as?
transferrin (diferric transferrin)
why are free ferrous ions bad?
can produce harmful oxygen radicals
binding of iron to proteins also serves to prevent ______ from having access to host iron
bacteria
T/F you excrete iron via shedding of skin
True
T/F most of your blood is excreted through the GI tract
true
T/F iron can be excreted via your urine
True
what does hepcidin do? where is it located?
what can it inhibit?
regulates iron entry into blood circulation, located in the liver
inhibits iron transport by binding to ferroportin which disables irons ability to transport out of the cell
increased iron inside the cell _____ production of Dcytb and DMT1 which _____ iron absorption
reduces, decreases
low levels of body iron ______ hepcidin levels which ______ Dcytb and DMT1 synthesis
decreases, increases
what is anemia?
when you lack enough healthy red blood cells or hemoglobin to carry oxygen throughout the body
What are the types of anemia? (multiple answers)
a. Thalassemia
b. Hemoplastic anemia
c. Vitamin deficiency anemia
d. Sideroblastic anemia
e. Megaloblastic anemia
f. Aplastic anemia
g. Rhabdohemogenic anemia
h. Sickle cell anemia
a,c,d,f,h
what are the two types of Thalassemia?
alpha and beta
which vitamin deficiencies can cause anemia?
folate (B9), vit B12, Vit C
pregnancy can cause a decrease in what vitamin which decreases iron absorption causing anemia
vit B9
causes of sideroblastic anemia?
alcohol use vit B6 deficiency lead poisoning copper deficiency excess zinc
how to treat iron deficiency anemia?
increase iron in diet
why supplement with Fe2+ instead of Fe3+?
Fe2+ is more soluble and has a higher bioavailability
how does hemochromatosis occur?
inc iron increases hepcidin which is the iron sensing protein, if it cannot sense iron it will keep storing it
if a patient is suffering from an influenza infection, what is a good thing to measure to determine iron status?
hematocrit
if a patient is suffering from an influenza infection, what is a bad thing to measure to determine iron status?
hemoglobin concentration in erythrocytes
what are some symptoms of anemia?
pale color of skin, lack of concentration, short attention span
what are some good indicators of anemia?
a. low iron
b. low copper
c. hematocrit test with high results
d. hematocrit test with low results
e. low red blood cell count
f. low white blood cell count
g. low hemoglobin
h. hypokalemia
a,d,e,g
whats the RDA for men/women? (premenopausal vs postmenopausal)
men: 8mg women: premeno 18mg, postmeno 8mg
how do you define an essential micromineral?
a mineral needed with an intake under 100mg/day
what is iron stored in the cell as? is it Fe2+ or Fe3+?
Ferritin, Fe3+
T/F oxidation of Fe2+ to Fe3+ occurs in the cell
True
what is the resulting phyrin product if heme is oxidized by heme oxygenase in the cell?
protoporphyrin
