Phosphate buffer Major intracellular buffer ·H+HPO2←H2PO4 OH+H2PO4←HO+H2PO42
Phosphate buffer • Major intracellular buffer • H+ + HPO4 2- ↔ H2PO4- • OH- + H2PO4 - ↔ H2O + H2PO4 2-
Protein Buffers Includes hemoglobin, work in blood and Isf Carboxyl group gives up h Amino group accepts ht Side chains that can buffer ht are present on 27 amino acids
Protein Buffers • Includes hemoglobin, work in blood and ISF • Carboxyl group gives up H+ • Amino Group accepts H+ • Side chains that can buffer H+ are present on 27 amino acids
2. Respiratory mechanisms Exhalation of carbon dioxide Powerful, but only works with volatile acids Doesnt affect fixed acids like lactic acid CO2+ H20 <>H2CO3 H HCO3 Body ph can be adjusted by changing rate and depth of breathin
2. Respiratory mechanisms • Exhalation of carbon dioxide • Powerful, but only works with volatile acids • Doesn’t affect fixed acids like lactic acid • CO2 + H20 ↔ H2CO3 ↔ H+ + HCO3 - • Body pH can be adjusted by changing rate and depth of breathing
3. Kidney excretion Can eliminate large amounts of acid Can also excrete base Can conserve and produce bicarb ions Most effective regulator of ph p If kidneys fail, ph balance fails
3. Kidney excretion • Can eliminate large amounts of acid • Can also excrete base • Can conserve and produce bicarb ions • Most effective regulator of pH • If kidneys fail, pH balance fails
№a++Hc0 H+H H2CO3 H*+ HCO3 CA H20+c0 HPO H2C03 NH NH4 H2PO4 CA C0,+H20
CO2 + H2O CA H2CO3 H2CO3 H + + HCO3 - HPO4 2- Na+ + HCO3 - CA H2O + CO2 H + NH3 H + NH4 + H2PO4 -