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28 Cards in this Set
- Front
- Back
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Respiratory Pigments...
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increase oxygen carrying capacity of blood by up to 50 fold or more
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The most widespread respiratory pigment?
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Hemoglobin, which all contain a heme group with iron and a protein globin
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Hemoglobin structure...
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Can be monomers, dimers, tetramers, or polymers, with a heme on each monomer that binds ONE Oxygen; blood usually tetramer
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Respiratory pigments are metalloproteins that...
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bind reversibly with O2, similar to enzyme and ligand
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Hemocyanins...
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contain copper, dissolved in blood of mollusks and arthropods
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What color is seen in oxygenated/deoxygenated respiratory pigments?
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Oxyhemoglobin (oxygenated) is red, deoxyhemoglobin is purplish
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Myoglobin...
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monomer found in muscle cells; an OXYGEN STORE rather than a transporter
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At increasing partial pressure of O2, a BLANK percentage of heme groups is oxygenated.
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A GREATER percentage of heme groups are oxygenated at increasing partial pressures of O2
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P50...
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partial pressure of O2 at which the hemoglobin is 50% saturated; a lower P50 means greater affinity
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Cooperativity of hemoglobin makes binding...
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Cooperativity between subunits makes binding of additional O2 molecules more likely if some are bound; causes sigmoidal shape to curve
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Total O2 vol % of blood in humans?
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20% maximally
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Oxygen delivery to tissues is greater during exercise than at rest due to BLANK
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due to venous reserve of O2
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Tissues in exercise have a BLANK PO2 which causes BLANK deoxygenation of hemoglobin than resting tissues
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In exercise have a LOWER PO2 which causes GREATER deoxygenation of hemoglobin than resting tissues
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Critical consequences of sigmoid curve
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better oxygenation at lungs and better delivery to tissues
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At lungs, a given change in blood saturation comes from?
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A large change in PO2
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At tissues, the same change in saturation comes from?
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A small change in PO2
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Compared to a monomer, a tetramer with cooperativity is...
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a better O2 transporter
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Animals with large O2 demands have greater...
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carrying capacities (ex: 30% vol in the seal)
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What conditions that occur in body tissues might influence oxygen affinity of blood?
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Lactic acid (drop in pH), temperature, carbon dioxide (converted to HCO3-)
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What effects would lower pH, higher CO2, and higher temp have on oxygen affinity?
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Lowers affinity, enhances delivery
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The Bohr Shift - affinity of hemoglobin...
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drops when pH drops and drops when CO2 partial pressure increases
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Venous blood vs arterial blood
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In venous, pH is lower and CO2 higher compared to arterial blood; the Bohr Shift will enhance O2 delivery
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Effects of temperature on oxygen equilibrium curve
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higher temperature lowers O2 affinity of hemoglobin
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The Haldane Effect
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oxygenated arterial blood holds less CO2 than deoxygenated venous blood
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Carbonic Anhydrase (CA)
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catalyzes interconversion of CO2 and HCO3-
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Where is CA found?
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In RBCs, and on lung and muscle epithelia; necessary for CO2 transport to take place
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Carbon Dioxide Equilibrium Curve of water breathing animals
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Steeper curve because they can excrete CO2 and HCO3- easily in water; their blood CO2 is lower than air breathers
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Venous blood takes up more CO2 than arterial...
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dropping it off at lungs or gills
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