Iron Metabolism

Iron

Ferrous (Fe2+) and ferric (Fe3+)

Oxidative reactions

<p>Transferrin, Ferritin, Lactoferrin</p> Signup and view all the answers

<p>In the heme moiety of erythrocytes (haemoglobin)</p> Signup and view all the answers

<p>Liver, meat, egg yolk, green leafy vegetables and whole grain cereals</p> Signup and view all the answers

<p>Heme iron</p> Signup and view all the answers

<p>3-4 g</p> Signup and view all the answers

<p>20-25%</p> Signup and view all the answers

<p>To hold iron for functional activity or for its storage and transport</p> Signup and view all the answers

<p>To transport oxygen</p> Signup and view all the answers

<p>Heme iron</p> Signup and view all the answers

<p>Liver and spleen</p> Signup and view all the answers

<p>Transferrin</p> Signup and view all the answers

<p>Myoglobin</p> Signup and view all the answers

<p>Ferritin</p> Signup and view all the answers

<p>Iron deficiency anemia</p> Signup and view all the answers

<p>Iron overload</p> Signup and view all the answers

<p>All of the above</p> Signup and view all the answers

<p>It produces ATP</p> Signup and view all the answers

<p>Vitamin C</p> Signup and view all the answers

<p>Transferrin transports iron to the cells</p> Signup and view all the answers

<p>Ferritin</p> Signup and view all the answers

<p>Carrying oxygen from the lungs to the tissues</p> Signup and view all the answers

<p>Storing oxygen in muscle cells</p> Signup and view all the answers

<p>Fatigue, weakness, and shortness of breath</p> Signup and view all the answers

<p>Damage to the liver, heart, and other organs</p> Signup and view all the answers

<p>Iron deficiency anemia</p> Signup and view all the answers

<p>Iron binds to the proteins to enable oxygen transport</p> Signup and view all the answers

<p>Liver and heart</p> Signup and view all the answers

<p>Heme iron</p> Signup and view all the answers

<p>All of the above</p> Signup and view all the answers

<p>Vegetarians</p> Signup and view all the answers

<p>All of the above</p> Signup and view all the answers

<p>Iron deficiency anemia</p> Signup and view all the answers

<p>Transporting iron throughout the body</p> Signup and view all the answers

<p>Storing iron in muscle cells</p> Signup and view all the answers

<p>Liver</p> Signup and view all the answers

<p>4 g</p> Signup and view all the answers

<p>Through sloughing of tissues</p> Signup and view all the answers

<p>Iron deficiency anemia</p> Signup and view all the answers

<p>Increased demand for iron</p> Signup and view all the answers

<p>Excessive iron absorption</p> Signup and view all the answers

<p>Therapeutic phlebotomy</p> Signup and view all the answers

<p>Duodenum</p> Signup and view all the answers

<p>Dcytb</p> Signup and view all the answers

<p>DMT1</p> Signup and view all the answers

<p>Ascorbic acid</p> Signup and view all the answers

<p>Ferritin</p> Signup and view all the answers

<p>Serum ferritin</p> Signup and view all the answers

<p>20-30%</p> Signup and view all the answers

<p>Desferrioxamine</p> Signup and view all the answers

<p>Saturation of serum transferrin</p> Signup and view all the answers

<p>Pathogenic microorganisms</p> Signup and view all the answers

<p>Vibrio vulnificus</p> Signup and view all the answers

<p>Death within 24 hours</p> Signup and view all the answers

<p>Serum transferrin</p> Signup and view all the answers

<p>Ferritin</p> Signup and view all the answers

<p>Vibrio vulnificus</p> Signup and view all the answers

<p>Rapidly progressive infection</p> Signup and view all the answers

<p>Iron Deficiency and Iron Overload</p> Signup and view all the answers

<p>Increased demand for iron, increased loss of iron, nutritional deficiency, inability to absorb iron, damage to the intestinal lining, and inflammation</p> Signup and view all the answers

<p>Microcytic and hypochromic red blood cells, low hemoglobin levels, and low serum ferritin values</p> Signup and view all the answers

<p>Examination for the cause and source of bleeding, iron supplementation, and transfusion with packed red blood cells if the deficiency is severe</p> Signup and view all the answers

<p>Genetic mutations, secondary factors such as blood transfusions or overdosing on iron pills or injections</p> Signup and view all the answers

<p>Cirrhosis and liver tumors, diabetes mellitus, and cardiac failure</p> Signup and view all the answers

<p>Dietary changes, therapeutic phlebotomy (periodic withdrawals of large amounts of blood), and avoiding iron supplements, iron-rich foods, alcohol, and raw or undercooked fish and shellfish.</p> Signup and view all the answers

<p>Liver, meat, egg yolk, green leafy vegetables, and whole grain cereals.</p> Signup and view all the answers

<p>Key role in synthesis of oxygen transporting and oxygen storage proteins. Formation of heme enzymes and other iron-containing enzymes involved in electron transfer and oxidation-reductions. DNA synthesis and repair.</p> Signup and view all the answers

<p>Heme iron is found in animal sources like meat, fish, and poultry, and is easily absorbed (high bioavailability). Non-heme iron is found in plant sources like dried beans, peas, fruits, and vegetables, and has relatively lower bioavailability.</p> Signup and view all the answers

<p>Vegetarians.</p> Signup and view all the answers

<p>Key role in synthesis of oxygen transporting and oxygen storage proteins. Formation of heme enzymes and other iron-containing enzymes involved in electron transfer and oxidation-reductions. DNA synthesis and repair.</p> Signup and view all the answers

<p>Heme iron is responsible for synthesis of oxygen transporting and oxygen storage proteins.</p> Signup and view all the answers

<p>Non-heme iron is involved in electron transfer and oxidation-reductions, as well as DNA synthesis and repair.</p> Signup and view all the answers

<p>To eliminate excess iron from the body</p> Signup and view all the answers

<p>Desferrioxamine</p> Signup and view all the answers

<p>Transferrin can be close to saturation, making small amounts of free serum iron available</p> Signup and view all the answers

<p>When an individual is overloaded with iron</p> Signup and view all the answers

<p>Vibrio vulnificus</p> Signup and view all the answers

<p>Death within 24 hours</p> Signup and view all the answers

<p>Via urine</p> Signup and view all the answers

<p>Iron supplementation</p> Signup and view all the answers

<p>Meat, fish, poultry</p> Signup and view all the answers

<p>The small intestine (largest amount absorbed in the duodenum by enterocytes of the duodenal lining)</p> Signup and view all the answers

<p>The free ion (ferrous form) or as heme iron (iron is split off from the porphyrin ring in the mucosal cytoplasm)</p> Signup and view all the answers

<p>Ferric reductase enzyme on the enterocytes’ brush border, duodenal cytochrome B (Dcytb)</p> Signup and view all the answers

<p>Divalent metal transporter 1 (DMT1)</p> Signup and view all the answers

<p>Ascorbic acid, HCl, iron deficiency</p> Signup and view all the answers

<p>Phytates (storage form of phosphates - abundant in cereals), tannins and other polyphenol compounds in fruits, tea coffee, red wine cocoa, achlorhydra GI disease, antacids, iron overload, gastric bypass surgery</p> Signup and view all the answers

<p>Ferritin</p> Signup and view all the answers

<p>Ferroportin</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>True</p> Signup and view all the answers

<p>Heme iron = Easily absorbed (high bioavailability) Non-heme iron = Relatively lower bioavailability</p> Signup and view all the answers

<p>Liver, meat, egg yolk, green leafy vegetables and whole grains cereals = Dietary Meat, fish and poultry = Animal sources Dried beans, peas fruits and vegetables = Plant sources</p> Signup and view all the answers

<p>Synthesis of oxygen transporting and oxygen storage proteins = Key role in oxygen transportation Formation of heme enzymes and other iron-containing enzymes = Involved in electron transfer and oxidation-reductions DNA synthesis and repair = Important for genetic processes</p> Signup and view all the answers

<p>Iron deficiency = Condition characterized by a lack of iron in the body Heme iron = Iron from animal sources which is easily absorbed Ferritin = Protein responsible for storing iron when it is not immediately needed Transferrin = Protein responsible for transporting iron throughout the body</p> Signup and view all the answers

<p>Iron overload = Can lead to cirrhosis and liver tumors Iron deficiency anemia = Caused by insufficient iron levels in the body Vibrio vulnificus infection in iron overloaded individuals = Can be rapidly progressive with high mortality</p> Signup and view all the answers

<p>Iron from animal sources is more easily absorbed than iron from plant sources = True Most of the iron in the body is contained in hemoglobin = True Hephaestin is a ferroxidase found mainly in the small intestine = True Heme iron is found in plant sources like dried beans and peas = False</p> Signup and view all the answers

<p>Ferroportin = Only known iron exporter in mammals Hephaestin = Ferroxidase that oxidizes Fe2+ to Fe3+ Cytochrome P450 = Reduces ferric iron (Fe3+) to ferrous iron (Fe2+) in the small intestine</p> Signup and view all the answers

<p>Iron Absorption = Major site of absorption is the small intestine Iron Transport = The protein involved in the transport of iron is transferrin Iron Storage = The major protein involved in the storage of iron is ferritin Iron Overload = Saturation above 50% of transferrin is indicative of this condition</p> Signup and view all the answers

<p>Ascorbic acid = Increases iron absorption Phytates = Inhibits iron absorption Tannins = Inhibits iron absorption Iron deficiency = Increases synthesis of DMT1, Dcytb, and ferroportin</p> Signup and view all the answers

<p>Dcytb = Reduces ferric iron (Fe3+) to ferrous (Fe2+) DMT1 = Transports iron across the enterocyte’s cell membrane Ferroportin = The only known iron exporter in mammals Hephaestin = Oxidizes Fe2+ to Fe3+</p> Signup and view all the answers

<p>Ferric Iron = Reduced to ferrous iron in the small intestine Heme Iron = Iron is split off from the porphyrin ring in the mucosal cytoplasm Non-Heme Iron = Inhibited by phytates and polyphenol compounds Transferrin-Bound Iron = Delivered mainly to bone marrow and liver</p> Signup and view all the answers

<p>Iron Deficiency = Increases transferrin synthesis Inflammation = Less iron is absorbed to deprive bacteria of iron Achlorhydra = Causes decreased absorption of iron Liver Disease = May lead to increased transferrin saturation</p> Signup and view all the answers

<p>Transferrin = Involved in the transport of iron in the blood Ferritin = The major protein involved in the storage of iron Hephaestin = Can oxidize Fe2+ to Fe3+ Apoferritin = Regulates iron absorption in response to the body’s needs</p> Signup and view all the answers

<p>Ferric Iron = Reduced to ferrous iron in the small intestine Heme Iron = Iron is split off from the porphyrin ring in the mucosal cytoplasm Non-Heme Iron = Inhibited by phytates and polyphenol compounds Transferrin-Bound Iron = Delivered mainly to bone marrow and liver</p> Signup and view all the answers

<p>Desferrioxamine = Forms a complex with iron and is eliminated via urine Transferrin = Binds iron for transport Ferritin = Stores iron when it is not immediately needed Hephaestin = Ferroxidase found mainly in the small intestine</p> Signup and view all the answers

<p>Iron overload = Serum transferrin value can be close to saturation, making small amounts of free serum iron available Iron deficiency = Lack of iron in the body Thalassemias = Bleeding is not an option Vibrio vulnificus infection in iron overloaded individuals = Rapidly progressive infection, with death ensuing within 24 h after ingestion of the meal</p> Signup and view all the answers

<p>Vibrio vulnificus = Marine bacteria, found in a small percentage of oysters and commercial shellfish Nonpathogenic microorganisms = Iron dependent and cannot compete against partially saturated transferrin in the normal individual Pathogenic microorganisms in iron overloaded individuals = Usually nonpathogenic microorganisms that can now become pathogenic due to iron overload Microorganisms in normal individuals = Entirely free of symptoms after consuming the same food as iron overloaded individuals</p> Signup and view all the answers

<p>Iron chelating therapy = Use of Desferrioxamine to eliminate excess iron from the body Iron overload = Condition characterized by an excess of iron in the body Ferrioxamine = Complex formed between Desferrioxamine and iron Thalassemias = Conditions where bleeding is not an option</p> Signup and view all the answers

<p>Iron absorption = Enhanced by factors such as vitamin C and acidic environment Iron excretion = Occurs via urine in iron chelating therapy Iron storage = Role of ferritin when iron is not immediately needed Iron transport = Role of transferrin</p> Signup and view all the answers

<p>Iron overload = Rapidly progressive infection with Vibrio vulnificus after ingestion of contaminated food Iron deficiency = Anemia Thalassemias = Complications arising when bleeding is not an option Infection in normal individuals = Entirely free of symptoms after consuming the same food as iron overloaded individuals</p> Signup and view all the answers

<p>Transferrin = Binds iron for transport Ferritin = Stores iron when it is not immediately needed Hephaestin = Ferroxidase found mainly in the small intestine Desferrioxamine = Forms a complex with iron for elimination</p> Signup and view all the answers

<p>Iron overload = No specific symptoms, but may lead to complications like infection Iron deficiency = Fatigue, weakness, shortness of breath Thalassemias = Complications when bleeding is not an option Vibrio vulnificus infection in iron overloaded individuals = Rapidly progressive infection, with death ensuing within 24 h after ingestion of the meal</p> Signup and view all the answers

<p>Rapidly progressive infection = Iron overload with Vibrio vulnificus infection Anemia = Iron deficiency Nonpathogenic microorganisms becoming pathogenic = Iron overload Lack of energy = Thalassemias</p> Signup and view all the answers

<p>Iron Deficiency Anemia = Hemoglobin &lt; 13 g/dl (male), 12 g/dl (female) Iron Overload = Iron content of the body can be elevated to values as high as 100 g in patients due to excessive absorption Iron Deficiency = The serum transferrin value (expressed as the total iron binding capacity) will be elevated with a serum iron saturation of less than 16 % Normal Iron Level = A loss of about 1 mg day–1 occurs in a healthy adult</p> Signup and view all the answers

<p>Iron Deficiency = Inability to absorb iron (use of acid reducing medications like proton pump inhibitors) Iron Overload = Overdosing on iron pills or injections</p> Signup and view all the answers

<p>Iron Deficiency = Management: a careful examination for the cause and source of bleeding Iron Overload = Therapeutic phlebotomy: Periodic withdrawals of large amounts of blood, where the iron is contained in the hemoglobin</p> Signup and view all the answers

<p>Iron Deficiency Anemia = Microscopic examination of blood shows characteristic microcytic (small in size) and hypochromic (under-pigmented) RBCs Iron Overload = The accumulation of iron in the liver, pancreas, and heart can lead to cirrhosis and liver tumors, diabetes mellitus, and cardiac failure respectively Iron Deficiency = Damage to the intestinal lining. (surgery involving the duodenum, which severely reduce the surface area available for absorption)</p> Signup and view all the answers

<p>Iron Deficiency = Functional or actual iron deficiency may be caused by Increased demand for iron, which the diet cannot accommodate Iron Overload = Iron overload also referred to as Hemochromatosis may be caused by; Genetic mutation (HFE gene) – associated with a marked inappropriate increase in iron absorption</p> Signup and view all the answers

<p>Iron Deficiency Anemia = The liver produces more transferrin, presumably attempting to maximize use of the little iron that is available (thereby increasing overall binding capacity) Iron Overload = Often used to describe hemochromatosis because it can lead to darkening of the skin and hyperglycemia Iron Deficiency = Microscopic examination of blood shows characteristic microcytic (small in size) and hypochromic (under-pigmented) RBCs</p> Signup and view all the answers

<p>Iron Deficiency Anemia = Bone marrow aspiration will reveal no storage iron to be present and serum ferritin values are virtually zero Iron Overload = Iron content of the body can be elevated to values as high as 100 g in patients due to excessive absorption Iron Deficiency = The serum transferrin value (expressed as the total iron binding capacity) will be elevated with a serum iron saturation of less than 16 % Normal Iron Level = A loss of about 1 mg day–1 occurs in a healthy adult</p> Signup and view all the answers