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9 Cards in this Set
- Front
- Back
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Hemoglobin(Hg) binds to O2 to form oxyHg, O2 attached to the Fe+2 in the heme. TRUE/FALSE
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TRUE.
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How is the affinity of Hg affected?
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It is affected by pH, temperature and the concentration in the cells of 2-3 biphosphoglycerate(2-3, BPG), 2-3 BPG and H+ compete with O2 for binding to deoxygenated Hg, decreasing the affinity of hemoglobin for O2 by shifting the positions of the 4 peptide chains(quartenary structure).
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What can happan when blood is exposed to certain drugs?
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When exposed to drugs and other oxidizing agents, the ferrous iron(Fe+2), that is normally in the molecule is converted to ferric iron(Fe+3), forming methemoglobin. It is dark colored and when present in large quantities in the circulation, it causes a dusky discoloration of the skin resembling cyanosis.
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Some oxidation of Hg to methemoglobin ocurs normally> TRUE/FALSE
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TRUE. An enzyme system in the RBCs, the NADH-methemoglobin reductase system, converts methemoglobin back to Hg.
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Can congenital absence of this system cause heredity methemoglobinemia?
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Yes.
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What is carbon monoxyHg?
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It is carboxyhemoglobin. This is formed when CO recats with Hg.
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Heme is also part of the structure of myoglobin, an O2 binding pigment found in red(slow) muscles. TRUE/FALSE
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TRUE.
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Where is neuroglobin found?
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It is found in the brain. It helps supply O2 to neurons.
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Does the respiratory chain enzyme cytochrome c contain heme?
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Yes.
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