I. Oxygen Transport in Blood<\/p>\n
A. Most oxygen has a reversible attachment to\u00a0hemoglobin<\/strong><\/p>\n O2<\/sub><\/em> + Hb <–> HbO2<\/sub><\/em><\/p>\n Hemoglobin (Hb) is a red pigment, but bright red when oxygenated and dull red-blue when deoxygenated.<\/em><\/p>\n B. Hemoglobin in most vertebrates & some invertebrates.\u00a0 About 98% of oxygen in mammals is carried by hemoglobin and a small amount is carried free in the plasma (liquid part of blood).<\/em><\/p>\n C. Hemoglobin has 4 globin subunits and an iron-containing heme portion that binds with the oxygen<\/p>\n Carbon Monoxide poisoning results in hypoxia due to CO binding to Hb about 200x more readily than oxygen.<\/em><\/p>\n D. Hemocyanins<\/strong>–\u00a0present in arthropods and some molluscs; carries oxygen<\/em><\/p>\n 1. Contain copper (not iron) bound to the protein<\/p>\n 2. Very large molecule<\/p>\n 3. Colorless when deoxygenated and blue when oxygenated<\/p>\n E.\u00a0Chlorocruorins<\/strong>–\u00a0carries oxygen in marine annelid worms<\/em><\/p>\n 1. Contains iron as heme. Reddish when concentrated but greenish in color when more dilute<\/p>\n 2. Contains globin molecules and is chemically related to Hb<\/p>\n 3. No considerable color change when oxygenated or deoxygenated<\/p>\n F. Hemerythrins<\/strong>–\u00a0carries oxygen in marine worms and hard valved invertebrates<\/em><\/p>\n 1. Has iron and protein but no heme<\/p>\n 2. Found inside circulating blood, coelomic cells and muscle cells<\/p>\n 3. Colorless when deoxygenated but violet-pink when oxygenated<\/p>\n G. Oxygen Hemoglobin Dissociation Curve<\/strong><\/p>\n \u00a0 \u00a0 \u00a0 \u00a0 Terminology to understand this curve seen you PowerPoint slide number 11 in the\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0Respiration part 5 slide set.<\/em><\/p>\n —Affinity is the oxygen being attracted to hemoglobin and once they attach to each\u00a0 \u00a0 \u00a0 \u00a0 \u00a0other, we use the term saturation and say that hemoglobin is saturated with oxygen.\u00a0 Oxygen will\u00a0 \u00a0saturate hemoglobin where oxygen levels are high – such as in the lungs.<\/em><\/p>\n \u00a0 \u00a0 \u00a0—Dissociation is oxygen pulling away from the hemoglobin and that way it is not\u00a0 \u00a0 \u00a0 \u00a0 \u00a0attached and free to go into a tissue that requires oxygen.\u00a0 Oxygen will dissociate from\u00a0 \u00a0 \u00a0hemoglobin in tissues were oxygen levels are low – such as an exercising leg muscle.<\/em><\/p>\n 1. Partial pressure of oxygen is the greatest determining factor on oxygen and hemoglobin dissociation (letting go of each other ) or saturation (attaching to each other)<\/p>\n 2. Tissues needing the oxygen get it, while oxygen and hemoglobin attach where tissues do not need the oxygen<\/p>\n 3. Shifting the curve to the left –higher affinity between oxygen and hemoglobin; higher pH, lower carbon dioxide level, lower temperature<\/em><\/p>\n 4. Bohr Effect: Shifting the curve to the right –lower affinity between oxygen and hemoglobin; lower pH, higher carbon dioxide levels, higher temperature, higher levels of metabolic byproducts (such as DPG)<\/em><\/p>\n 5. Root Effect:increase in carbon dioxide plus decrease in pH not only cause a Bohr Effect but also the Root Effect when there is a reduction in the oxygen carrying capacity of the respiratory pigment (hemoglobin). This can release oxygen into solution and is the mechanism important in filling swim bladders with oxygen. Seen in some fish, cephalopods and crustaceans<\/em><\/p>\n II. Carbon Dioxide Transport in Body Fluids<\/p>\n A. Carbon dioxide diffuses from an area of higher pressure to lower pressure, but pressure gradient is not as great as with oxygen.\u00a0\u00a0Frogs compensate for this by having a huge skin surface area for carbon dioxide exchange.<\/em><\/p>\n B. Most (~70%) carried as bicarbonate ions in the plasma (some free in plasma, and some attached to the globin portion of hemoglobin<\/em>)<\/p>\n CO<\/strong> 2<\/sub><\/em><\/strong>\u00a0+H<\/strong> 2<\/sub><\/em><\/strong>O <–> H 2<\/sub><\/em><\/strong>CO3<\/sub><\/em><\/strong>\u00a0<–> H+<\/sup><\/em><\/strong>\u00a0<\/sup><\/em><\/strong>+ HCO3<\/sub>–<\/sup><\/em><\/strong><\/strong><\/p>\n Enzyme for the formation of carbonic acid is carbonic anhydrase.<\/p>\n C. Chloride shift<\/p>\n D. Carbon Dioxide equilibrium curve –rapid increase in CO2<\/sub><\/em>\u00a0<\/em>content at relatively low PCO2\u00a0<\/sub><\/em>in blood; and a continued, but slower increase as PCO2<\/sub><\/em>\u00a0rises. Blood does not become saturated with CO2\u00a0<\/sub><\/em>as it does with O2<\/sub><\/em><\/p>\n E. Haldane Effect –Deoxygenated blood can carry more CO2<\/sub><\/em>\u00a0<\/em>than oxygenated blood. <\/em>The Haldane effect is that deoxygenation of hemoglobin at the tissues promotes CO2<\/sub><\/em>\u00a0uptake by the blood whereas oxygenation of the hemoglobin at the respiratory surface promotes CO2<\/sub><\/em> unloading.\u00a0 Deoxygenated hemoglobin pushes the equation shown above in B. to the right and increases the amount of carbon dioxide that can be carried in the form of bicarbonate ions.\u00a0 Oxygenated hemoglobin pushes the equation shown above in B. to the left so that carbon dioxide is produced and may be exhaled.<\/em><\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" I. Oxygen Transport in Blood A. Most oxygen has a reversible attachment to\u00a0hemoglobin O2 + Hb <–> HbO2 Hemoglobin (Hb) is a red pigment, but bright red when oxygenated and dull red-blue when deoxygenated. B. Hemoglobin in most vertebrates & … Continue reading