BIO 203 Lecture Notes - Lecture 6: Electrochemical Gradient, Nernst Equation, Resting Potential
16 Nov 2016
School
Department
Course
Professor
Document Summary
Surrounds all the tissues in our body. Composed of all solutes that are dissolved in plasma water, plus large solutes, proteins. Based on charge of ions, not number of positive/negative ions. Total body water (tbw) = 42 l or 60% body weight. Ecf = 14 l or (cid:1151) tbw. Interstitial fluid = 11 l or 80% of ecf. Plasma = 3 l or 20% of ecf. Plasma and interstitial fluid are nearly the same but, plasma has a higher protein concentration. Ecf & icf are in osmotic equilibria. Ecf & icf are in chemical disequilibrium. Ecf & icf are in electrical disequilibrium. Sodium ion is 12x more concentrated in ecf than icf. Potassium is 30x more concentrated in icf than ecf. Lipid permeability - membrane is not a barrier because moving through lipids isn"t an issue. Insertion of specific membrane - spanning integral proteins. Allow movement of large molecules and ions.
