BIO 2110 Lecture Notes - Lecture 3: Metalloprotein, Hemoglobin, Partial Pressure

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18 Jul 2014
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Steady state: rate o2 consumption = rate o2 added to blood at lungs, rate co2 produced equals rate co2 leaves blood at lungs. Gas diffuses from high partial pressure to low: delta po2 drives o2. From blood to tissue: delta pco2 drives. Solubility of oxygen in aqeuos fluids is low. Metalloproteins (respiratory pigments: proteins containing metal ions which reversibly bind with o2, increase o2 carrying capacity 50 fold, haemoglobin. Oxygen is transported in the blood: dissolved plasms 2, reversibly combined with haemoglobin 98% = oxygenation. Haemoglobin has 4 identical subunits each with a heme group containing iron: hb can carry 4 o2 molecules. Oxygenation of haemoglobin exhibits cooperativity: binding of each o2 molecule makes it easier for the next to bind, release of each o2 molecule makes it easier for the next to release, oxygen affinity. Po2(50) (50 percent saturation) inverse to affinity. Three ways: small amount are transported in plasma (10%)