-nitric oxide: vasodilator important for propping open tiny vessels; levels decline as blood is
stored in blood banks
+it is one of many factors that will affect how the RBCs carry oxygen
-Gases dissolve in liquids. Partial pressure of a gas in a liquid is defined as the partial pressure of
that same gas in the gas phase at equilibrium.
-Example: start with water with 0 partial pressure of oxygen (in equilibrium with a gas sample
that has no oxygen in it whatsoever) and then bring it into contact with some oxygen gas
+Result: the oxygen gas will dissolve in the water
+At equilibrium, the partial pressure of the oxygen gas in the air and in the water is equal.
Low oxygen solubility means concentrations are not equal. Partial press
+what is in the gas phase at equilibrium must be in the liquid phase, so 100mm Hg partial
pressure of oxygen in the gas phase means there must be 100 mm Hg partial pressure of oxygen
in the liquid phase at equilibrium
+the oxygen concentration in both the liquid and the gas, however, is different.
Oxygen is not very soluble in water. Carbon dioxide is 20 times more soluble in water.
[gas] in solution = (solubility of gas)(P gas)
-more carbon dioxide has dissolved in the water at equilibrium [much more solubility in water
than oxygen is]
-we carbonate our drinks and not oxygenate our drinks b/c would not increase the oxygen in
water by a factor of 20
Your question: what if both gases are present (do they affect each other)? No, they don’t
affect each other unless they chemically react with each other.
Partial pressure of oxygen=100 mm Hg
Partial pressure of carbon dioxide = 100 mm Hg
in the water
Partial pressure of oxygen = 100 mm Hg Partial pressure of carbon dioxide = 100 mm Hg
-ideal gas law (PV=nRT) only relevant for the gas phase, not for the liquid phase
Oxygen is not very soluble in water. Hemoglobin increases solubility of oxygen in blood.
Hemoglobin is inside red blood cells. Fig 16-6
-Ahemoglobin molecule is composed of four protein globin chains, each surrounding a central
-only packed inside RBCs
-each heme group can bind to _____________(check this)
Individual gas components will diffuse from areas of higher partial pressure to areas of
lower partial pressure
-Gases diffuse down partial pressure gradients
-oxgyen decreased from outside to inside alveoli and more carbon dioxide in the alveoli (b/c
bring in fresh oxygen into the alveoli which moves really reall