HNF 462 1st Edition Lecture 22Outline of Last LectureI. Sources of Vitamin KII. Digestion and Absorption of Vitamin KIII. Transport and Storage of Vitamin KIV. Excretion of Vitamin KV. Blood Clottinga. Importance of Vitamin Kb. Role of Calciumc. Formation of the ClotVI. Anticoagulantsa. Heparinb. Warfarinc. Calcium ChelatorsVII. Bone Mineralizationa. Osteocalcinb. Calcium ParadoxVIII. Other Functions of Vitamin KOutline of Current LectureI. Trace MineralsII. CofactorsIII. Interlinked to Biochemistry and BehaviorIV. Electron Transport ChainV. Zinc DeficiencyVI. Iron Food SourcesVII. Zinc Food SourcesVIII. Copper Food SourcesThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.IX. Iron Absorptiona. Heme Ironb. Non-heme Ironc. Hemochromatosis Current Lecture: Iron, Zinc and Copper Pt 11. Trace Mineralsa. Three major: iron, zinc, and copperb. Transimition metals = trace mineralsc. Intake is low, but very important for body functiond. Present in the body in low amounts2. Cofactorsa. Synonymous to batteries: body uses as power to fuel reactions in the body3. Interlinked to Biochemistry and Behaviora. Pica: develops if mineral deficient; develops appetite for earth substancesb. Geophagy: the deliberate consumption of earth substances4. Electron Transport Chaina. Iron and copper used in ETCb. Iron and copper need to be directed towards the mitochondria so they can be used for energy production, otherwise they have the ability to form free radicalsc. (Zinc is directed towards the nucleus for RNA/DNA synthesis)5. Zinc Deficiencya. Zinc deficiency is the most common soil deficiencies, therefore making it one of the most common nutrient deficiencies in humansb. Not so much a problem in the US because have resources to put zinc back into the soil6. Iron Food Sourcesa. Meat, poultry, and fish (muscle has high storage of iron)b. Milk, cheese (low absorption because iron is bound to a protein that humans cannot easily digest)c. Enriched grainsd. Legumes, dark leafy vegetables (non-heme iron: iron is bound to other compounds so not as easily absorbed because must compete)e. Iron Contamination: iron potf. Iron Poisoning7. Zinc Food Sourcesa. Seafoodb. Red Meatc. Eggsd. Nuts and seedse. Cereals (not well absorbed)f. Zinc is bound to proteins, so any food with a high protein content will be a good source of zinc8. Copper Food Sourcesa. Seafoodb. Nuts and seedsc. Grains9. Iron Absorptiona. Iron stores in the body are monitored when iron is first absorbedi. Iron is ingested and then stored in the mucosal cells in the intestineii. If iron stores in the body are high, then the body will excrete the iron throughshed intestinal cellsiii. If iron stores in the body are low, then body will release iron to transferrin for absorptionb. Heme Iron: found in animal productsi. Heme transporter protein is expressed in the intestinal microvilli: releases iron inside the intestinal cell for storage in mucosal ferritin (ideal mechanism)c. Non-heme Iron: found in plant foods, poorly absorbedi. Ferric iron ferrous iron is transported into intestinal cell by DMT1 (also transports cobalt, albumin) for storage is mucosal ferritinii. Enhancing Factors:1. MFP factor: factor associated with meat, fish, and poultry2. Ascorbic Acid (vitamin C)iii. Inhibiting Factors: 1. Phytates and fibers: Non-heme iron competes with phytates and oxalates for absorption = lower absorption rate2. Calcium and phosphorus in high intakes3. EDTA in food additives4. Tannic acid5. Polyphenols6. Oxalatesd. Hepcidin: stops absorption of iron if the body does not need iti. Negative impact on iron absorption into the blood streame. Ferroportin: transports iron out of the intestinal celli. If hepcidin is present, ferroportin is degraded so iron cannot be transported, and instead it will be excretedf. Hemochromatosis i. The body does not have the mechanisms to control iron absorptionii. Signal from hepcidin binding to cells is lostiii. Increases iron levels in the
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