Respiring tissue Capillary blood cO Dissolved CO2 gas 广一co2+ plasma protein+ Carbamino compounds 23% cO co2+H Hbco, Chloride shift c 70% Co2 cO+0、AH H2CO3+HCO3 +H+ 98.5% 2 O2+HHb+HbO2 +H 0 m1.5% 2 Dissolved Oz gas
Transport of oxygen a Chain β Chain a Forms of oxygen transported Chemical combination: 98.5% Physical dissolution: 1.5% Fe+t atom Porphyrin molecule ■ Hemoglobin(血红蛋白,Hb) is essential for the transport of O2 by blood
Transport of oxygen ◼ Forms of oxygen transported – Chemical combination: 98.5% – Physical dissolution: 1.5% ◼ Hemoglobin (血红蛋白，Hb) is essential for the transport of O2 by blood
CH CH=CH. CH3 C NFe—N CH2 C C CH=CH2 CH CH 2 CH 3 N CH Globin polypeptide Hemoglobin is the gas-transport molecule inside erythrocytes Oxygen binds to the iron atom Heme attaches to a polypeptide chain by a nitrogen atom to form 1 subunit of hemoglobin Four of these subunits bind to each other to make a single hemoglobin molecule
• Hemoglobin is the gas-transport molecule inside erythrocytes. • Oxygen binds to the iron atom. • Heme attaches to a polypeptide chain by a nitrogen atom to form 1 subunit of hemoglobin. • Four of these subunits bind to each other to make a single hemoglobin molecule
Two forms of hb a Deoxygenated state(deoxyhemoglobin) when it has no oxygen a Oxygenated form(oxyhemoglobin carrying a full load of four oxygen
Two forms of Hb ◼ Deoxygenated state (deoxyhemoglobin) -- when it has no oxygen ◼ Oxygenated form (oxyhemoglobin) -- carrying a full load of four oxygen
8 8 High PO2 Hb+ O2 HbO2 LoW PO
Hb + O2 HbO2 High PO2 Low PO2