14
chapter 1
Water, Acids, Bases, and Buffers
TABLE 1-5
Concentration o f Cations and Anions in Plasma Water and Interstitial Fluid
*
Plasma Water ’
Interstitial Fluid*
Ion
mEq/L
mmol/L
mEq/L
mmol/L
Cations
Na+
153.2
153.2
145.1
145.1
K+
4.3
4.3
4.1
4.1
Ca2+
3.8
1.9§
3.4
1.7
Mg2+
1.4
0.7 K
1.3
0.65
Total
162.7
160.1
153.9
151.6
Anions
c i-
111.5
111.5
118
118
HCO
3
-
25.7
25.7
27
27
H
2
P0
4
--H P 042-
2 . 2
0 . 6 6
2.3
0.7
Other
6.3
5.9
6 . 6
6 . 2
Protein
17.0
1.5
0
0
Total
162.7
145.3
153.9
151.9
Total mOsm per liter
305.4
303.5
♦Reproduced, with permission, from D. M. Woodbury in
P h y s io lo g y a n d B io p h y s ic s.
T. Ruch, H. Patton, and A. Scher, Eds. (Saunders, 1974).
"'"Plasma water content assumed to be 93%.
^Gibbs-Donnan factors used as multipliers are 0.95 for monovalent cations, 0.9 for divalent cations, 1.05 for monovalent anions, and 1.10 for
divalent anions.
"Total Ca is 2.7 mmol/L; ionized Ca is about 70% of total Ca.
"Total Mg is 1
mmol/L; ionized Mg is about 65% of total Mg.
FIGURE 1-12
Fluid mosaic model of a membrane consists of lipids and proteins. Globular proteins are interspersed within the lipid
matrix: Protein A traverses the entire bilayer; protein B is embedded in one leaflet; proteins C and D are on the periphery.
