Osmoregulation Flashcards
osmosis
tendency of H2O to move between two solutions of different osmolarity separated by a barrier permeable only to H2O
Low Osmolarity
fewer solute particles, higher water conc.
High Osmolarity
More solute particles, Less water conc. as hydration shells form around the molecules
what is osmotic pressures opposing force?
Hydrostatic pressure
osmotic pressure can be described in two way…
(1) osmolarity (mmol/L)
2) osmolality (mOsm/kg
Osmolarity
measure of the concentration of a particular solute (Na+) per L
Osmolality
measure of the osmoles of (all) solutes per kg of solvent
whats the Na+ osmolarity of SW?
400-450 mmol/L
what is the osmolality of SW?
1000-1100 mOsm/kg
whats the Na+ osmolarity of FW?
0.3 mmol/L
what is the osmolality of FW?
0.7-10 mOsm/kg
water volume can change with ambient temperature? T/F
True
What defines a electrochemical gradient?
Two parts
(1) Electro- differ in charge across the membrane
(2) chemical- differ in solute conc. across membrane
Donan Equilibrium
An Electrochemical equilibrium is reached but there is an unequal amount distribution of charge molecules due to a diff. charged molecule that is impermeable to membrane
Nernst Equation
used to calculate the imbalance of ions caused by Donan equilibrium