TRANSPORT OF OXYGEN & CARBON DIOXIDE IN BODY FLUIDS
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TRANSPORT OF OXYGEN & CARBON DIOXIDE IN BODY FLUIDS OUTLINE
1/6 Chemical properties and distributions of respiratory pigments2/6 O2-binding characteristics of respiratory pigments3/6 Functions of respiratory pigments in animals4/6 CO2 transport5/6 Acid-base physiology6/6 PBLTransport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2 OUTLINE
1/6 Chemical properties and distributions of respiratory pigmentsTransport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2
Developing mammalian fetus recieves O2 and voids CO2 by means of close juxtaposition of its own blood vessels with those of its mothers circulatory systemOUTLINE
1/6 Chemical properties and distributions of respiratory pigmentsTransport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2
O2 crosses mothers blood to fetuss blood by diffusion through tissues in placentaOUTLINE
1/6 Chemical properties and distributions of respiratory pigmentsTransport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2
basic options for gas transfer mode:-countercurrent gas exchange;cross-current gas exchange;cocurrent (concurrent) gas exchangeOUTLINE
1/6 Chemical properties and distributions of respiratory pigmentsTransport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2 4 chemical categories recognized:-hemoglobinshemocyaninshemerythrinschlorocruorins
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1/6 Chemical properties and distributions of respiratory pigmentsTransport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2 Many of their important chemical properties resemble properties of enzyme proteins.HOWEVER, respiratory pigments are NOT functionally enzymes.
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1/6 Chemical properties and distributions of respiratory pigmentsTransport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2 Characters of respiratory pigments vs enzymes:-combination at defined binding sites;highly specific binding sites;noncovalent & weak bonding;
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1/6 Chemical properties and distributions of respiratory pigmentsTransport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2 Characters of respiratory pigments vs enzymes:-O2 is ligand of hemoglobin (when hemoglobin combines with O2, molecular conformation changed);
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1/6 Chemical properties and distributions of respiratory pigmentsTransport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2 Characters of respiratory pigments vs enzymes:-affinity of hemoglobin for O2 (ease of hemoglobin binding with O2)
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1/6 Chemical properties and distributions of respiratory pigmentsTransport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2 Characters of respiratory pigments vs enzymes:-other ligands (allosteric ligands / allostreric modulators: H+, CO2) for hemoglobin
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1/6 Chemical properties and distributions of respiratory pigmentsTransport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2 Characters of respiratory pigments vs enzymes:-allosteric ligands / allostreric modulators bind to hemoglobin affect bind of primary ligand (O2)
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1/6 Chemical properties and distributions of respiratory pigmentsTransport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2 Characters of respiratory pigments vs enzymes:-allosteric ligands / allostreric modulators bind to hemoglobin: modifying conformation & flexibility
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1/6 Chemical properties and distributions of respiratory pigmentsTransport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2 Hemoglobin:multisubunit protein (consist > 2 proteins bonded together by noncovalent bonds)multisubunit hemoglobins have O2-binding site on each subunit
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1/6 Chemical properties and distributions of respiratory pigmentsTransport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2 Hemoglobin:cooperativity among substrate-binding sites: binding of O2 to any one site affects how readily other sides bind O2Difference with enzyme: they dont modify ligand
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2/6 O2-binding characteristics of respiratory pigmentskey for understanding functions of respiratory pigments : oxygen equilibrium curve @ oxygen dissociation curve;Human has approximately 5.4x1020 heme groups per 100mL blood;Combination of O2 with each individual O2- binding site is stoichiometric;Transport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2 Transport of O2 and CO2 in body fluidsOUTLINE
3/6 Functions of respiratory pigments in animalsrespiratory pigments presently known to carry out at > 8 different functions;aid routine transport of O2O2 storesbuffers of blood pHCO2 transportincrease rate of O2 diffusion through cytoplasm of cellsenzymesnonrespiratory transport rolestissue functions other than O2 supply (regulation of mitochondrial respiration)Animal Physiology Transport of O2 & CO2 OUTLINE
4/6 CO2 transportCO2 dissolves in blood as CO2 molecules, but only small fraction (about 5% in human arterial blood);reactions when CO2 dissolves in aqueous solutions:-CO2 + H2O = H2CO3 (carbonic acid)CO2 + H2O = HCO3- + H+ (CO2 acts as an acid in aqueous systems)H2CO3 = H+ + HCO3- (bicarbonate can then dissociate to carbonate CO32- and additional proton)
Transport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2 OUTLINE
5/6 Acid-base physiologypH of body fluids cannot vary far from normal level without serious functional consequences;normal human blood pH at 37oC is 7.4;a person will lie to death if pH as high as 7.7 @ as low as 6.8;abnormal H+ concentrations affect functions of proteins;Transport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2 OUTLINE
6/6 PBLA person has involved in an accident and suffered some blood loss. Discuss the consequences of that condition to the body and how to overcome the problems.Transport of O2 and CO2 in body fluidsAnimal Physiology Transport of O2 & CO2 OUTLINE
Diving feats and behaviourTypes of dives and importance of methodPhysiologyO2 stores of diversCirculatory adjustments during divesMetabolism during divesAerobic dive limitDecompression sicknessPossible advantage for pulmonary O2 sequestration in deep divesO2 CO2 and internal transport at work: Diving by marine mammalsAnimal Physiology Transport of O2 & CO2 OUTLINE
Hill, R. W., Wyse, G. A. & Anderson, M. 2008. Animal physiology (2nd ed.). Sinauer Associates Inc.
Animal PhysiologyO2; CO2& Internal TransportReferencesOUTLINE
Chemical properties and distributions of respiratory pigmentsO2-binding characteristics of respiratory pigmentsFunctions of respiratory pigments in animalsCO2 transportAcid-base physiologyAnimal PhysiologyO2; CO2& Internal TransportTransport of O2 and CO2 in body fluidsOUTLINE
CirculationHeartsA: Circulatory in simple animals
B: Circulatory in complex animalsOpen circulatory systemClosed circulatory system (Cardiovascular System)AdaptationStructural differences of arteries, veins and capillaries correlate with their functionsSingle and Double CirculationO2 CO2 and internal transport at work: Diving by marine mammalsAnimal PhysiologyO2; CO2& Internal Transportproperties of gasesdiffusion in gasesconvective transport of gasescontrasting physical properties of air & waterrespiratory environment
Animal Physiology O2; CO2 & Internal TransportO2 & CO2 physiologyO2 and CO2 - respiratory gasses.O2is not actively transported in animal.CO2 sometimes actively transported across cell membranes (bicarbonate ions HCO3-) by reaction with waterThus condition must be favourable for passive transport to cells:-Fan worms: elaborate circulatory system; filled with blood rich in hemoglobin-like O2- transport pigment; spectacular tentacles (gills).Water beetle: bubble that act as gill while beetle underwater (O2 moves steadily into bubble from water when beetle submerged).Animal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyAnimal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiology
Animal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiology
Exchanges of respiratory gasses - usually most urgent. A person dies within minutes if denied O2, but can live for days without exchanging nutrients, nitrogenous wastes or water. WHY? - O2as final electron acceptor in cellular respiration.Animal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyEnergy cannot be transfered from bonds of food molecules to bonds of ATP by aerobic catabolic apparatus of a cell unless O2 is available to combine with e- exiting the electron-transport chain.CO2 accumulation in body rapidly acidify body fluids & harmful.Animal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiology
2 mechanisms how respiratory gases move from a place to another:-simple diffusionconvection (bulk flow)CHEMICAL POTENTIAL: provides basis for a truly general law of diffusion. DIFFUSION:-Animal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiology[regions of high chemical potential]rate proportionate to difference in chemical potential[regions of low chemical potential]Diffusion within a single aqueous solution:-[solute] is useful surrogate for chemical potential because [solute] gives correct answers if used in diffusion equations.
Diffusion between gas mixtures and aqueous solutions:-Concentration is not useful surrogate for chemical potentialPartial pressure is useful in expressing chemical potential for gasses
Animal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyAnimal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyOxygenNitrogenArgonCarbon DioxidePercent of all gas
20.9578.080.930.04Partial pressure in atmosphere
0.20950.78080.00930.0004Total = 1 atm1 atm1 atm1 atm1 atmAnimal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyproperties of gasesgases exist in air; other types of gas mixtures & dissolved in aqueous solution.in aqueous solution, gas molecules distributed among H2O molecules in same way glucose molecules / Na+ ions incorporated among H2O molecules
Animal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyproperties of gases
Law of partial pressures:- TOTAL PRESSURE EXERTED BY A MIXTURE OF GASES (IE ATM) IS SUM OF INDIVIDUAL PRESSURESEXERTED BY EACH OF SEVERAL COMPONENTGASES IN THE MIXTURE.
Individual pressure exerted by any particular gas in a gas mixture is PARTIAL PRESSURE of that gas.
PARTIAL PRESSURE of each gas in a mixture is independent of other gases present.
gases in gas phaseAnimal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyproperties of gases
Each component gas behaves in terms of its partial pressure in a volume of mixed gases as if it was alone occupying the entire volumeThus partial pressure ofgases in gas phaseOxygenNitrogenArgonCarbon DioxidePercent of all gas
20.9578.080.930.04Partial pressure in atmosphere
0.20950.78080.00930.0004Total = 1 atm1 atm1 atm1 atm1 atmeach gas in a gas mixture isPV = nRT (calculated from universal gas law) where:-P = pressure n = number of moles (gas quantity)V = volume R = universal gas constantT = absolute temperature Animal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyproperties of gases
Proportion of gases in a mixture expressed in fractional concentration.Mole fractional concentration of a particular gas in a mixture is fraction of total moles of gas present. gases in gas phaseOxygenNitrogenArgonCarbon DioxidePercent of all gas
20.9578.080.930.04Partial pressure in atmosphere
0.20950.78080.00930.0004Total = 1 atm1 atm1 atm1 atm1 atm ie. In a volume of dry atmospheric air near sea level, O2 mole is 20.95% of total moles of all gases. Therefore mole fractional concentration of O2 in dry air is 0.2095Animal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyproperties of gases
Proportion of gases in a mixture expressed in fractional concentration.Volume fractional concentration of a particular gas in a mixture is fraction of total volume of gas present.gases in gas phaseOxygenNitrogenArgonCarbon DioxidePercent of all gas
20.9578.080.930.04Partial pressure in atmosphere
0.20950.78080.00930.0004Total = 1 atm1 atm1 atm1 atm1 atm ie. If we remove O2 from a volume of dry atmospheric air at given temp and pressure, final volume will be 20.95% less than original volume when same temp and press are restored.Animal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyproperties of gases
Hence the partial pressure exerted by each gas in a mixture = its fraction (mole fractional concentration or volume fractional concentration) of the total pressure.gases in gas phaseOxygenNitrogenArgonCarbon DioxidePercent of all gas
20.9578.080.930.04Partial pressure in atmosphere
0.20950.78080.00930.0004Total = 1 atm1 atm1 atm1 atm1 atmPx = FxPtot Px = partial pressure of a particular gas Fx = mole or volume fractional concentration of the particular gas Ptot = total pressure of a gas mixtureAnimal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyproperties of gases
partial pressure (tension) of a gas in an aqueous solution is equal to partial pressure of the gas in gas phase with which the solution is at equilibrium.
gases in aqueous phaseO2-free waterO2 (0.21atm)Animal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyproperties of gases
partial pressure (tension) of a gas in an aqueous solution is equal to partial pressure of the gas in gas phase with which the solution is at equilibrium.
gases in aqueous phaseO2 (0.21atm)O2 (0.21atm)EQUILIBRIUMAnimal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyproperties of gases
partial pressure (tension) of a gas in an aqueous solution is equal to partial pressure of the gas in gas phase with which the solution is at equilibrium.
gases in aqueous phaseO2 (0.21atm)O2 (0.19atm)Animal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyproperties of gases
partial pressure (tension) of a gas in an aqueous solution is equal to partial pressure of the gas in gas phase with which the solution is at equilibrium.
gases in aqueous phaseO2 (0.21atm)O2 (0.19atm)O2O2O2O2Animal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyproperties of gases
partial pressure (tension) of a gas in an aqueous solution is equal to partial pressure of the gas in gas phase with which the solution is at equilibrium.
gases in aqueous phaseO2 (0.19atm)O2 (0.19atm)EQUILIBRIUMAnimal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyproperties of gases
Partial pressure and concentration of gas in aqueous solution is more complicated than in gas.HENRY's LAW: fundamental law that relates partial pressure and concentration in aqueous solutions.gases in aqueous phaseAnimal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyproperties of gases
Several ways HENRY's LAW is expressed, employing different but related coefficients:-absorption coefficient: dissolved concentration of a gas when the partial pressure of the gas in solution is 1 atm.Cx = APx Px = partial pressure of the gas (x) in solution Cx = dissolved concentration of a gas A = absorption coefficientgases in aqueous phaseAnimal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyproperties of gases
Cx = APx In gas phase (Cx proportionate to Px):-all gases have essentially identical quantitative relations between Cx and Px (all adhere to universal gas law).In aqueous phase:-A varies based on a) type of dissolved gas; b) type solution of gas, depending on temperature and salinity of watergases in aqueous phaseAnimal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyproperties of gases
Cx = APx Absorption coefficient (A) is measure of gas solubility:-High A = high solubility (a lot of gas dissolve at any given partial pressure).Three important characteristics of gases dissolved in aqueous solutions when examining A:-Solubilities of different gases are different.Solubilities of gases in aqueous solutions decrease strongly with increasing water temperature.Solubilities of gases in aqueous solutions decrease with increasing salinity.
gases in aqueous phaseAnimal PhysiologyO2; CO2& Internal TransportO2 & CO2 physiologyproperties of gases
gases in aqueous phaseSolubilities of different gases are different.N2
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