1. 1 Comparative physiology Lecture -2- Oxygen (Respiration – Atmosphere) P(5-15)

2. 2 Oxygen important Cellular respiration Diffusion Co 2 and O 2 : opposite

3. 3 IV. A Road Map for Cellular Respiration Cytosol Mitochondrion High-energy electrons carried by NADH High-energy electrons carried mainly by NADH Glycolysis Glucose 2 Pyruvic acid Krebs Cycle Electron Transport Figure 6.7

4. 4 The molecules of e - transport chains are built into the inner membranes of Mitochondria  The chain acts like a chemical machine that uses Energy released by the “fall” of e - to pump H + across inner mt membrane. Figure 6.12 Protein complex Electron carrier Inner mitochondrial membrane Electron flow Electron transport chain ATP synthase  These hydrogen ions build up a charge  store potential energy

5. 5 Composition of dry atmosphere Dry is not the exist Water is abundant in our atmosphere

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9. 9 The “Greenhouse Effect” Greenhouse gases are transparent to shortwave but absorb longwave radiation Thus the atmosphere stores energy  The Earth’s surface thus receives energy from two sources: the sun & the atmosphere –As a result the Earth’s surface is ~33C warmer than it would be without an atmosphere

10. 10 1. Shorter, high Energy wavelengths Hit the earths Surface 2. Incoming energy Is converted to heat

11. 11 3. Longer, infrared Wavelengths hit Greenhouse gas Molecules in the atmosphere 4. Greenhouse gas Molecules in the Atmosphere emit Infrared radiation Back towards earth

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13. 13 The “Greenhouse Effect In spite of oxygen decreasing We can live As burrows --soil is less oxygen because !!!

14. 14 Water vapor in air It has partial pressure ZERO Temperature ---- (4.6)mm.Hg

15. 15 I. Properties of gases Gay-Lussac’s Law: either the pressure or the volume of a gas is directly proportional to absolute temperature if the other is held constant.

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17. 17 Water vapor cont Pp (WATER VAPOR) 37 c IS 46mm.Hg in lung. 100% relative humidity If pp is decrease will expressed as %. At 100 c 760 mm.hg so will boil If atm prusser 17.5 ---will boil 20c

18. 18 I. Properties of gases Dalton’s Law: the partial pressure of each gas in a mixture is independent of the other gases present. The total pressure equals the sum of the partial pressures of all the gases present. P TOTAL = P 1 +P 2 +P 3 …. Henry’s Law: the quantity of gas that dissolves in a liquid at a given temperature is proportional to the partial pressure of that gas in a gas phase. [G] = P gas x S gas

19. 19 The total pressure exerted by a mixture of gases

20. 20 Altitude and atm pressure at 3000 m highest ( reduction of physical performance) 6000 m (barely survive) 1300m no respiration after But O 2 is remain 20.95 Why !!!!

21. 21 Partial Pressures Partial pressure of oxygen: PO 2 PO 2 = P atm X [O 2 ] atm [O 2 ] atm =.209 –fractional concentration –constant throughout atmosphere Sea level –P atm = 760mm Hg, PO 2 = 159 Mt. Everest –P atm = 235mm Hg, PO 2 = 49

22. 22 altitude and atmospheric pressure - Normal dray air hve PpO 2 = 159mm.Hg -6000m At P = 380mm.Hg -PpO 2 = 80mm.Hg

23. 23 By calculating At Atmospheric pressure 20 20 X.209= 4.18 is not correct with inhalid air why!!!!

24. 24 Total p =( pp1+pp2+pp3) We have water vapor 47mm.Hg in our lung so what is remain for oxygen

25. 25 Solubility of gases Henry’s Law: the quantity of gas that dissolves in a liquid at a given temperature is proportional to the partial pressure of that gas in a gas phase. [G] = Pgas x Sgas

26. 26 Solubility of gases Increasing temperature ----decrease solubility At 15c and atm Pp of gas O 2- ----34.1 ml/ liter water N------16.9 ml / lit water CO 2 -------1019.1 ml / liter water

27. 27 Salinity / temperature

28. 28 Tension of Gas in solution Tension of gas in solution in equilibrium with gas tension in atmosphere Tension = Pp

29. 29 Solubility of CO 2 and its rat of diffusion Volume dissolved = 1019 x 0.03/100= 0.3 ml CO 2 /liter -CO2 is more soluble but its volume is small -Carbonate and bicarbonate in natural water water PH sea water = 8.2 and CO 2 ( 34ml-56ml)/liter o.3 CO 2 + Hco 3( MAJOR)

30. 30 Processes that affect partial pressures of O 2 and CO 2 within an environment

31. 31 Isolated tidal pool 6am-4pm : day ( p CO 2= 0.0001, Po 2= 555) 4pm- 8pm: open ( p CO 2 = 0.2, Po 2= 151) 8pm – 6 am : night (p CO 2= 2.7, Po 2= 1.6) Pp mm.Hg

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33. 33 Gas diffusion Between lungs or gills and atm Rat inversely proportional with molecular Wight 44----= 6.6 co 2 32 -------= 5.6 O 2 Co 2 diffusion is 0.85 of oxygen diff But co 2 appear faster than oxygen why!!

34. 34 Gas diffusion If equal pps of carbon dioxide and oxygen Are exerted on closed water Co 2 solubility 30 times of oxygen 30 * 0.86= 25.6 Solubility affect diffusion 25.6 times of oxygen If equal Pps only.

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36. 36 Contrasting physical properties of air and water Gases diffuse more readily through air than water Water more dense and viscous Salt water dissolves less O 2 Solubility of O 2 decrease as temp. increases Water-breathing animals must work harder to obtain a given quantity of oxygen

37. 37 Comparing water and air At 15 c water has 7 ml o 2 /liter Wight 0.01gm / 1000 gm To obtain an amount 100000 times must move on respiratory organs Air has 209 ml of o 2 weight 280mg Remainder 791mg To obtain an amount 3.5 times must move on respiratory ograns

38. 38 Comparing water and air Water oxygen 0.7% Air oxygen 21% So how aquatic acclimatized 1- unidirectional Viscosity : energy,time 2- small area for diffusion Air on lung by millimeters On water parts of ml

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40. 40 High [O 2 ] –0.209:  p O 2 diffuses fast –“D”: Fick’s Law Gases must dissolve in water –Keep epithelia moist –Evaporative water loss Low density, viscosity –Easy to move Low [O 2 ] –0.007:  p O 2 diffuses slowly –“D”: Fick’s Law Gases already dissolved –Water, water everywhere High density, viscosity –Hard to move Air Water