Gas transport

• relates PO2 of blood (how much available) to how much is bound to Hemoglobin • s shaped (sigmoid) curve • blood has both dissolved and bound O2 • curve is more sigmoid if there is a greater change in affinity

• PO2 (free O2) decreases • Affinity (ease of O2 access) increases • hyperbolic curve • P50 –> affinity (globin state)

how easy is it for O2 to bind - measured by P50 = PO2 when at 50% saturated (1/2 Mb has O2 bound)

helps unload oxygen into tissues at a high PO2 - creates a partial pressure gradient that drives diffusion into tissues

not active site for O2 attachment (bohr effect)

shift of curve to the left in lungs (more sigmoid shape) -CO2 enhances O2 delivery into tissues - CO2 in tissues binds to hemoglobin & becomes more tense - O2 affinity decreases, O2 unloads - O2 diffuses into mitochondria

baby - low DPG, high affinity, left shifted curve mother- high DPG, low affinity, right shifted curve

height of curve = oxygen carrying capacity (respiratory pigment in blood)

by altering respiratory pigment physiology • increase concentration of respiratory pigment • modify O2 binding properties of pigments (daphnia) • alter preexisting pigments (fish decrease ATP & GTP within red blood cells after being placed in water low in O2

Haldane effect = O2 enhances CO2 unloading at the lungs + CO2 loading at the tissues - acts as a buffer in the blood -bound w/ O2 is a strong acid - hemoglobin (producing more H+) - TISSUE = PO2 low, loading (higher affinity) - LUNG = PO2 high, unloading (lower affinity)