BIOL 003 Lecture Notes - Lecture 23: Carbonic Anhydrase, Hemoglobin, Heme
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Co2 transportation in blood: 7% dissolved in plasma. Co2 + h2o (at tissue) h2co3 co2 + h2o (at lungs) Catalysed by enzyme carbonic anhydrase: 23% binds with haemoglobin (hb) in rbcs. Co2 + hb hbco2 (carbaminohaemoglobin) co2 + hb (at lungs: 70% combines with water in rbcs. Moves into plasma to form nahco3 (sodium bicarbonate) rbc now. Moves out, cl- ions from plasma move into rbc to balance charge ( chloride. Co2 + h2o h2co3 h+ + hco3. Reverse reaction due to partial pressure difference in co2. Bicarbonate re-enters rbc cl- ions move out ( reverse chloride shift") O2 transportation in blood: 1. 5% dissolved in plasma, 98. 5% transported in haemoglobin (hb) 1 haemoglobin = 4 globin chains 1 haem (iron compound) in the middle of each. Each iron in haem binds to one o2. Oxyhaemoglobin forms (hb with 4 o2 molecules one bound to each haem)
