Transcript Document
Spring M Dahl, MS, PhD Prepared by: Jeanette Andrade MS,RD,LDN,CDE Kaplan University What are we going to be learning about tonight? Electrolytes: Sodium, Potassium Bone Minerals: Calcium, Phosphorus, Magnesium Antioxidants: Iron, Zinc, Selenium Electrolytes: substances that become ions in solution and acquire the capacity to conduct electricity Cation: positive charged ion Anion: negative charged ion Hydroxyapatite: calcium phosphate salt Antioxidant: Reduces oxidative damage such caused by free radicals Reactive Oxygen Species: molecules and ions of oxygen that have an unpaired electron Zinc Finger Motif: sequence of approximately 30 amino acids, forming a helix-turn-helix, believed to form a structure that includes tetrahedrally coordinated zinc (II) ions Major positive cation in fluid outside of the cells Regulates total amount of water in the body Transmission of sodium in and out of cells regulates brain, nervous system and muscles functions Normal blood sodium level is 135-145 mEq/L What can happen if there is too much sodium in the cells or too little? Major cation found inside cells The proper amount of potassium is essential for regulation of heart rate and muscle function Normal lab values are 3.5-5.0 mEq/L What happens if there is too little potassium or too much potassium in cells? Not really a cycle, this diagram is depicting active transport of molecules across a membrane. Active transport is coupled to ATP hydrolysis to obtain enough energy to transport ions against their concentration gradient. outside Plasma membrane inside NEED ACTIVE TRANSPORT TO PUMP AGAINST A GRADIENT Accounts for 1-2% of adult human body weight Body stores 99% of calcium in bones and teeth It is needed to contract and expand muscles and blood vessels RDA: 19-70 year old males need 1000-1200 mg of calcium per day RDA: 19-70 year old non-pregnant/lactating females need 1000-1200 mg of calcium per day What foods tend to have calcium in them? TOXICITY Not from high intake of calcium from foods, but from supplementsKidney stones occur from an increased calcium excretion from kidneys DEFICIENCY Abnormal parathyroid function and rarely due to low dietary intake since calcium is a large reservoir in bones Chronic kidney disease, vitamin D deficiency, low magnesium in blood Chronically low dietary calcium intake may prevent peak bone mass Majority of phosphorous is found as phosphate within the body 85% of phosphorous is found within the bone Major structural component of bone in the form of hydroxyapatite What else is phosphorus important for within our bodies? RDA for males and females 19-70 year old 700 mg/day What foods contain phosphorous? TOXICITY Calcification of nonskeletal tissues- most commonly the kidneys DEFICIENCY Loss of appetite, anemia, muscle weakness, bone pain, rickets, osteomalacia, and can possibly lead to death 60% is within the skeletal structure, 27% within the muscles, 6-7% within the cells and 1% outside of cells Magnesium is required for ATP synthesizing protein in the mitochrondrion What other important processes is Magnesium important for? What foods contain Magnesium? RDA for males 31-70 years old: 420 mg/day RDA for females 31-70 years old: 320 mg/day TOXICITY Not with foods, but with salts- magnesium salt DEFICIENCY Main problem diarrhea Rare due to kidneys are able to reduce urinary excretion when intake is low Occur with gastrointestinal disturbances, renal disorders, chronic alcoholism, age Oxygen transport and storage Electron transport and energy metabolism Antioxidant: why? Catalase and peroxidase are heme containing enzymes that protect cells against an accumulation of harmful hydrogen peroxide (ROS) White blood cells engulf bacteria and expose them to ROS in order to kill them We produce or own disinfectant (clorox) What foods contain Iron? RDA for males 19-70 years old: 8 mg/day RDA for females: 19-49 years old: 18 mg/day 50-70 years old: 8 mg/day TOXICITY Accidental overdose with iron containing products Genetic disorders usually are the cause Hereditary Hemochromotosis Hereditary anemias DEFICIENCY Most common deficiency in the world, 3 levels of iron deficiency Storage iron depletion Early functional iron deficiency Iron deficiency anemia Zinc functions in the cell can be divided into 3 categories: Catalytic: enzymes depend on Zinc for reactions Structural: for proteins and cell membranes; Zinc finger motif Regulatory: Zinc finger motif regulates gene expression by acting as transcription factors Antioxidant: Why? Some studies suggest that Zinc is a protective factor against atherosclerosis by inhibiting the oxidation of LDL by cells or transition metals (copper, iron) – Protect cells against Tumor Necrosis Factor induced cell injury What foods contain Zinc? RDA for males 19-70 years old: 11 mg/day RDA for females 19-70 years old: 8 mg/day TOXICITY Occurs from consumption of food or beverages that have been contaminated with zinc released from galvanized containers DEFICIENCY Severe: generally from a genetic disorder Mild: generally children from developing countries, however occurs in pregnant, anorexics, aging individuals, celiac disease and irritable bowel disease Selenoproteins: Glutathione peroxidases Thioredoxin reductase Iodothyronine deiodinases Antioxidant: Why? Glutathione peroxidase- antioxidant enzymes that reduce ROS by coupling their reduction to the oxidation of glutathione – Thioredoxin- Thioredoxin reductase participates in the regeneration of several antioxidants What foods contain Selenium? RDA for males and females 19-70 years old: 55 uG/day TOXICITY Accidental or suicidal ingestion of grams of selenium DEFICIENCY Decreased activity of glutathione peroxidase, thioredoxin reductase and thyroid deiodinases Chronically ill patients receiving total parenteral nutrition (TPN) Treating metabolic disorders such as phenylketonuria (PKU) NADH ASCR reductase Example of antioxidant control systems of oxidative stress in cells Exogenous radical-X Vit C O2 Vit C Extracellular Space Vit E Vit E LOOH O CoQ10 Plasma Membrane PLA2 CoQ10 LOOH Minerals/metals Fe Se NAD(P)H+H GSH- Se Px Other Coenzyme Q Lipoic acid GSH reductase GSSG NAD(P)+ + Vitamins Niacin Vitamin E Vitamin C Cytosol 2 GSH Cyt-b5reductase or NQO1 Endogenous radical-X NADPH NADP+ LOH G-6-PDH Detoxification Glucose-6P 6-P-gluconate Burgess, J. R. and J. E. Andrade (2006). Antioxidant Effects of Citrus Flavonoid Consumption. Potential Health Benefits of Citrus. B. S. Patil, E. G. Miller, N. D. Turner and J. S. Brodbelt. Washington, DC, An American Chemical Society Publication. How do minerals play into the “big” biochemistry picture? Are supplements needed by the average consumer? Your “take-away” message? How do you feel about this course now that we are at the end? Do you see application of this material as you advance your education and consider your professional goals? Overall thoughts on the course?