Skildum: Electrolytes Flashcards
What is EAR?
Estimated Average Requirement. The average daily nutrient intake level estimated to meet the requirements of half of the healthy members of a particular life stage and gender group.
What is RDA?
Recommended Daily Allowance. The average daily dietary nutrient intake level sufficient to meet the nutritional requirements of nearly all (97-98%) healthy persons in a particular life stage and gender group
What are the major minerals in the body?
Ca phosphorus K Na, Cl Mg
What are the major trace elements in the body?
Iron
Zinc
Copper
Manganese
What are the ultratrace elements in the body?
Selenium
Molybdenum
Iodine
Chromium
Molybdenum
four human enzymes require it sulfite oxidase, xanthine oxidoreductase, aldehyde oxidase, and mitochondrial amidoxime reductase
Chromium
Role in insulin sensitivity, binds chromodulin, an insulin receptor binding protein
Selenium
Role in antioxidant proteins; de-iodinases in the thyroid: Selenocysteine
Iodine
thyroid hormone
What is the major extracellular cation?
Na
What is the major intracellular cation?
K
What is hte most abundant metal ion in the body?
Ca (mostly in bone)
What are the dietary sources of Ca?
dairy seafood turnip broccoli kale supplements
What are the fxns of Ca?
bone mineralization
blood clotting
muscle contraction
metabolism regulator
How is Ca absorbed?
- Saturable carrier mediated transport (TRPV6 transports Ca across the brush border membrane> calbindin chaperones Ca in the cell> Ca/ATPase transports Ca across the basolateral membrane)
- Pericellular transport around tight jxns (claudin)
What regulates Ca absorption?
calcitrol
What increases Ca absorption?
Vit D
sugars; sugar alcohols
protein
what decreases Ca absorption?
fiber
phytic, oxalic acids
divalent cations (Mg, Zn)
unabsorbed fatty acids
How much Ca is in the blood?
8.5-10 mg/dL
40% bound to protein (albumin)
50% free ionized Ca
10% complexed w/ sulfate, phosphate, citrate
What is the cytosolic conc of Ca in cells?
LOW 100nmol
How does the extracellular conc of Ca differ from the intracellular?
10,000x higher (2.3 mmol)
Where is Ca stored?
intracellular compartments (mitochondria, ER)
How is Ca exported from cells?
Ca/2Na exchanger- low affinity, high capacity transporter
Ca/2H exchanger is a high affinity, low capacity transporter
What is is the affect of the Ca -calmodulin complex?
Stimulates:
- Calcineurin> inhibits Ca channels
- MLCK> muscle contraction
- Ca/calmodulin kinase> inhibits glycogen synthase
- phosphorylase kinase> phosphorylase