HNF 462 1st Edition Lecture 27Outline of Last LectureI. Selenium-Containing Protein vs. SelenoproteinII. Selenium ExcretionIII. Se RDA and DeficiencyIV. Se Toxicity and Assessment V. Iodine Sourcea. Iodization VI. Iodine Absorption, Transport, and StorageVII. Production of Thyroid HormoneVIII. Functions of IodineIX. Physiological Effects of Thyroid HormonesX. Iodine RDA and DeficiencyXI. Potassium Iodide for Radiation ProtectionXII. Nutrients that Affect Thyroid FunctionOutline of Current LectureI. Sources and Forms of Vitamin EII. Digestion, Absorption, and TransportIII. BioavailabilityIV. StorageV. ExcretionVI. Reactive Oxygen Species (ROS)VII. Cellular AntioxidantsVIII. Physiological Functions of ROSIX. Cell Proliferation and DeathCurrent Lecture: Vitamin E and AntioxidantsThese 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.1. Sources and Forms of Vitamin Ea. Two forms: tocopherols and tocotrienolsi. RRR configuration of alpha-tocopherol is most biologically active formb. Plant oils are richest sources, but also found in animal products (associated with fat)2. Digestion, Absorption, and Transporta. Digestioni. Isoforms of vitamin E need FAs removed by esterasesb. Absorptioni. In intestine ii. Passive diffusionchylomicronslipoproteiniii. Transported to liver via chylomicron remnant, then packed into VLDL (only alpha-tocopherol form)c. Cellular Absorptioni. Receptor-mediated endocytosisii. Lipoprotein lipase activityiii. HDL-mediated nutrient delivery3. Bioavailabilitya. Large range (20-80%) based on dietary fat intake levelsb. Enhancers: fat with mealc. Inhibitors: fat malabsorption diseases4. Storagea. Not stored in a single organb. 90% vitamin E is unesterifiedi. Stored in fat droplets of adipose tissueii. Release of vitamin E form adipose tissue is very slow5. Excretiona. Primarily excreted via feces (released into bile excretion through feces)6. Reactive Oxygen Species (ROS)a. Natural by-product of normal metabolism of oxygenb. Formation of free radicals can cause damage to cells7. Cellular Antioxidants: Counteract the effects of free radicalsa. Enzymesi. Superoxide dismutase (SOD)ii. Glutathione peroxidase (GPX)iii. Catalaseb. Small Moleculesi. Glutathioneii. Thiolsiii. Vitaminsiv. Phytochemicals8. Physiological Functions of ROSa. Precise regulation of ROS is needed because have a purpose in the body, but if concentration is too high, can cause damageb. Mediate immune responsec. Signal transductiond. Products of aerobic metabolismi. ETC: formation of free radical by oxygen’s uptake of an electronii. NADPH oxidase9. Cell Proliferation and Deatha. ROS is involved in the balance of cell proliferation and
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