Term
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Definition
| protein, main cytoplasmic component of erythrocytes. Oxygen carrying componet of the RBC |
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Term
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Definition
MAintain homeostasis by facilitating cellular respiration.
Delivers oxygen to tissues from lungs.
Pulls CO2 away from tissues.
Balances pH. |
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Term
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Definition
| Hgb is able to do this because it can reversibly bind with oxygen, Hgb picks up O2 in the lungs and transports it via the RBCs to the oxygen-poor tissues where it releases O2. |
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Term
| Pulls Carbon Dioxide Away |
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Definition
| Hgb can do this because of its ability to bind gases of cellular waste, picks up CO2 from tissues and transports it to the lungs to be exhaled. |
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Term
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Definition
| Hgb contributes to the bicarbonate buffer system by binding or releasing Hydrogen atoms. |
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Term
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Definition
| More alkaline, CO2 combines with water to produce carbonic acid allow hydrogen ions to be released and causes pH to decrease. |
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Term
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Definition
| more acidic, carbonic acid dissociates to release hydrogen and bicarbonate, blood pH raises. Bicarbonate travels to the lungs to be exhaled. |
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Term
| Basic Hemoglobin Structure |
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Definition
4 heme groups, 2 pairs of unlike polypeptide chains.
Protein with a non protein. |
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Term
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Definition
| Protoporphyrin Ring (carbon, hydgrogen, nitrogen), atom of ferrous iron, each heme is positioned in a pocket of the polypetide chain, site of oxygen binding. |
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Term
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Definition
| 2 pairs of unlike polypeptide chain, bracelets of amino acids linked together. |
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Term
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Definition
| comprised of 141-146 amino acids each, sequence and number is determined by structural genes, variations give rise to different types of polypeptide chains. |
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Term
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Definition
| occurs during RBC development, ends in the reticulcyte stage. |
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Term
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Definition
| occurs in the mitochondria of the RBC precursor, iron is transported in the primiteve rBC and proceeds to the mitochondria, iron combines with Protoporphyrin IX. |
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Term
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Definition
| occurs in the ribosomes, using mRNA they are translated into polypeptide chains. |
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Term
| How do Heme and Globin come together? |
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Definition
| each globin chain pairs off with a heme once released from the ribosome, an aglobin and a non-aglobin binds forming a heterodimer, 2 heterodimes combine to form a tetramer. |
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Term
| Hemoglobin Structure After Synthesis |
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Definition
| tetrameric molecule. 4 polypeptide chains : 2 A globin, 2 non A globin/ 4 Heme groups: 1 heme per polypetide, has the ability to carry ONE oxygen. an average RBC contains 640 million tetramers. |
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Term
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Definition
Hemoglobin A - 2a and 2 b
Hemoglobin A2 - 2a and 2 d
Hemoglobin F - 2a and 2 Gamma |
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Term
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Definition
| Molecule fully saturated with oxygen, carries oxygen from the lungs to the tissues. |
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Term
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Definition
| returing to the lungs with CO2 from tissues. O transport is based on the affinity for Hgb to bind oxygen. |
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Term
| Increased Oxygen Tension (^pO2) |
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Definition
| Oxygen tension is high inside the lungs, Hgb has a higher affinity for oxygen, O2 Molecule binding increses the affinity allowing Hgb to be completely oxygenated, resulting in oxyhemoglobin. |
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Term
| Decreased Oxygen Tension (downpO2) or (^pCO2) |
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Definition
| oxygen tension is low inside the tissues, Hgb has less affinity for oxygen where tension is low, allows O2 to be released, resulting in deoxyhemoglobin. |
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Term
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Definition
any of the following causes Hgb to bind to O with less affinity:
^ in blood Co2
Decrease in pH
^ in 2,3-DPG
^ in temperature |
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Term
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Definition
| Increased CO2 results in decreased Hgb Affinity for oxygen |
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Term
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Definition
When pH falls, Hgb loses its affinity for oxygen, it lowers due to the presence of lactic acid and CO2, facilitates the release of oxygen to tissues.
When pH rises, Hgb gains an affinity for oxygen, faicilates the release of CO2 and the binding of oxygen. |
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Term
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Definition
| 2,3-dpg binds deoxyhemoglobin, and acts to stabilize the molecule, increased 2,3dpg makes it harder of oxygen to bind Hgb and more likely to be released, Increased oxygen uptake in the lungs casues 2,3 dpg to be expelled. 2,3 dpg is high when near respiring tissues, and low when in lungs. |
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Term
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Definition
| binding of carbon monoxide to the heme iron. Hgb has 200 times more affinity for CO. Hgb is incapable of transporting oxygen. .2-.8% normal, smokers as high as 4-30% |
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Term
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Definition
| when ferrous iron becomes ferric. Incapable of combining reversible with oxygen, usually aquired due to durgs or chemicals (reversible), inherited, 1.5% normal. |
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Term
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Definition
| chemically modified, irreversible oxidation of Hgb by drugs and chemicals, 100 times less affinty for oxygen, rarely exceeds 10%. |
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Term
| Normal Erythrocyte Destruction |
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Definition
| aged red blood cells are phagocytized. Hgb is kept at normal levels, Bone marrow continues steady production. Main way RBCs die normally. |
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Term
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Definition
| premature destruction of RBCs, reduced number of RBcs leads to reduced tissue oxygenation, Increased RBC production, possible anemia. |
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Term
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Definition
| 90% of hemolysis, destruction outside a blood vessel, usually by macrophage, occurs in spleen, liver, marrow, lymph nodes, monocytes. |
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Term
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Definition
| 10% of hemolysis, destruction of a RBC within a blood vessel. |
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Term
| Extravascular process for recycling Heme |
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Definition
macrophage lyse the phagocytized erythrocyte.
Hgb hydrolyzed into heme and globin.
Globin Metabolism
Heme metabolism |
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Term
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Definition
| globin portion of hemoglobin is broken down into amino acids which are released into the peripheral blood. |
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Term
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Definition
| Iron released from heme, returned to plasma, once in plasma iron is bound to transferrin and carried to bone marrow where it is recycled. Protoporhyrin into biliverdin, then bilirubin, biliruin into bloodstream, picked up by liver, secreted with bile metabolized into urobilinogen, excreted. |
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Term
| Intravascular Process of Hgb Recycling |
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Definition
| Hgb is recycled for RBCS removed by the intravascular process, RBCs lyse in-vivo and the Hgb is released to the periphereal blood, captured by haptoglobin, carried to liver where it is phagocytized, then breakdown follows extravascular process. |
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