BIOL 118 Lecture Notes - Lecture 9: Oxygen Saturation, Hemoglobin, Partial Pressure
11 Dec 2015
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Figure 45. 2 - oxygen makes up 21 percent of the atmosphere, but its. Total pressure for the mixture of gases is equal to the sum of partial pressures of individual gases. Diffusion of gases depends on partial pressures not % gases. Percent pressure multiplied by the atmospheric pressure give the partial pressure. Hard to breathe at high altitudes bc there is lower diffusion gradient btwn atmospheric and partial pressure. P2-p1 = difference in partial pressures of gases on either side of barrier to the diffusion. D = distance (thickness of barrier to diffusion. Oxygen moves from high partial pressure to lower. Oxygen saturation - how much oxygen is bound to hemoglobin (hb) 100% saturated - hb is fully saturated with o2. 0% saturated - no o2 in the hb. Cooperative binding - binding of one o2 to hb makes it easier to binge successive o2 molecules. Consequence - hb will become saturated with o2 even at low po2 gradient.
