Cofactors Flashcards
Calcium and Phosphates
Deposited in bones, phosphorus follows Ca
Two forms of calcium
- Calcium phosphate in bones and teeth
- Free calcium: rqrs transmembrane transport for neuromusc function, membrane work, signal pathways (calmodulin), and clotting cascade
Plasma calcium regulation
- Low plasma Ca, PTH released from Parathyroid leading to calcium liberation from bone via osteoclasts, increased calcium absorption in gut, and increased renal calcium resorption
- High plasma calcium: calcitonin released from thyroid leading to calcium deposition in bone via osteoblasts and decreased renal resorption
Sodium
plays role in blood pressure regulation, water follows sodium
Potassium
Action potentials
Chlorine
Digestion (HCL) macrophage killing (HOCl) ridding body of CO2 (Cl/bicarb exchange)
Iron
Important in redox reactions (ex = cytochrome oxidase), very toxic in free state as it binds to proteins and disrupts function and structure. Most bound to hemoglobin
Ferritin
Intracell Iron storage prevalent when iron stores are low, unbound = apoferritin
Hemosiderin
Intracell iron storage, prevalent when iron stores are high
Transferrin
extracell/ plasma transport. Receptors on intestinal membrane bind iron-transferrin complex and is exocytosed and dissolved to Fe-3 and transferrin. Fe-3 is reduced to Fe-2 by duodenal cytochrome B (ferric reductase, with Vit C). Intracell Fe-2 is transported by DMT1
Iron def
anemia, most common nutrient deficiency. Occurs after stores are depleted. Can occur due to hemorrhage. In males this indicates malignancy
Hemosiderosis
Fe overload, can induce free radical formation (Fenton) allows for nonpathogenic bacteria to grow (V Vulniferous)
Hemochromatosis
Progressive hemosiderosis, can be genetic, damages body. Found in alcoholics due to increased iron absorb, potentially lethal
Copper
Important in redox reactions (ascorbic acid oxidase and tyrosinase). Functions in many metalloenzymes. Most bound to ceruloplasmin, rest bound with albumin or complexed with histidine. Elevated in hyperglycemia.
Def Copper
Menk’s disease = kinky hair syndrome. Copper based enzymes don’t function and is fatal
Cu Toxicity
Wilsons Disease is a defect in copper transporters besides ceruloplasmin which is increased. Biliary excretion is blocked leading to liver and brain damage
Zinc
Important in binding NAD (alchohol dehydratase). Functions in many metalloenzymes and transported via albumin. Stored via metallothionein (also stores cadmium and arsenic) synth increased by heavy metals and protects the cell from their toxic effects
Zinc Def
Wernecke Korsakoff Syndrome (alchs)
Zn and Vit B1 def leading to poor growth, aerodermatitis enteropathica = hair loss and diarrhea
Manganese
acts as electron sink (histidine ammonia lyase, mitchondrial superoxide dismutase). Often replaced by Mg due to easy access from plants
Magnesium
Useful for ATP binding, excreted via kidneys
Cobalt
Part of cobalamine coenzyme (vit B12) and is in only two enzymes:
methymalonyl CoA mutase and homocysteine methyl transferase
Nickel
Catalytic site for urease
Molybdenum
Important for redox reactions (Xanthine oxidase)
Vanadium
Redox rxns (nitrate reductase)
