Tutorial:How do we get the oxygen we breathe: Difference between revisions

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Hemoglobin captures oxygen and transports it through the bloodstream by binding oxygen to each of its <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/Four_hemes/3'>four heme groups</scene>. These <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/One_heome/2'>heme groups</scene> are prosthetic groups; they are non-protein chemical compounds that are associated with hemoglobin and are necessary for its function. Each heme is <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/Heme_composition/1'>ring molecule made up of</scene> {{Template:ColorKey_Element_C}}arbon, {{Template:ColorKey_Element_N}}itrogen, {{Template:ColorKey_Element_O}}xygen and hydrogen, with a single <font color="#E06633">'''Fe<sup>2+</sup>'''</font> (iron) ion at its center, coordinated by the four surrounding nitrogens. Each heme is roughly <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/Planar_heme/1'>planar</scene>, and is held in place within the monomer by a hydrophobic interactions and a covalent bond between the iron ion and a nitrogen atom in the side chain of what is termed the <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/Proximal_histidine/1'>proximal histidine</scene>. Another histidine, termed the <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/Distal_histidine/2'>distal histidine</scene>, helps in oxygen binding by preventing oxidation of the iron atom (which would prevent oxygen from binding) and by preventing other molecules from binding.
Hemoglobin captures oxygen and transports it through the bloodstream by binding oxygen to each of its <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/Four_hemes/3'>four heme groups</scene>. These <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/One_heome/2'>heme groups</scene> are prosthetic groups; they are non-protein chemical compounds that are associated with hemoglobin and are necessary for its function. Each heme is <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/Heme_composition/1'>ring molecule made up of</scene> {{Template:ColorKey_Element_C}}arbon, {{Template:ColorKey_Element_N}}itrogen, {{Template:ColorKey_Element_O}}xygen and hydrogen, with a single <font color="#E06633">'''Fe<sup>2+</sup>'''</font> (iron) ion at its center, coordinated by the four surrounding nitrogens. Each heme is roughly <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/Planar_heme/1'>planar</scene>, and is held in place within the monomer by a hydrophobic interactions and a covalent bond between the iron ion and a nitrogen atom in the side chain of what is termed the <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/Proximal_histidine/1'>proximal histidine</scene>. Another histidine, termed the <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/Distal_histidine/2'>distal histidine</scene>, helps in oxygen binding by preventing oxidation of the iron atom (which would prevent oxygen from binding) and by preventing other molecules from binding.


When oxygen is abundant, an <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/Heme/1'>oxygen molecule binds to the iron</scene> in the heme group. (''THINK'': Are there other changes besides the oxygen binding to the iron ion? Why might there be other changes?) We can watch oxygen binding in the <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/Heme/2'>context of an entire monomer</scene> (colored in rainbow colors from the N terminus of the monomer to its C terminus) or in a <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/Heme/1'>close-up view</scene> of the heme group.
When oxygen is abundant, an <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/Heme/1'>oxygen molecule binds to the iron</scene> in the heme group (Molecular oxygen (O<sub>2</sub>) is represented by two red spheres). (''THINK'': Are there other changes besides the oxygen binding to the iron ion? Why might there be other changes?) We can watch oxygen binding in the <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/Heme/2'>context of an entire monomer</scene> (colored in rainbow colors from the N terminus of the monomer to its C terminus) or in a <scene name='User:Jaime_Prilusky/How_do_we_get_the_oxygen_we_breathe/Heme/1'>close-up view</scene> of the heme group.
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