03 Hemoglobin

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• component of RBC, carries O2

• blue and red: globin chains

• green: heme, 4 in a hemoglobin

Globin

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• sickle cell: abnormal hemoglobin

Heme

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• porphyria: defects in enzymes making the porphyrin

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• RBC with BPG Mutase makes 2, 3 BPG

• bad for red cells: sacrifices ATP (pyruvate normally used to make ATP)

Hemoglobin Binding

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• favored in tissues to release O2. T for tissues

• relaxed form favored in lungs to pick up more O2

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• myoglobin: bind each O2 molecule equally, linear increase until plateau

• hemoglobin: S shaped curve. Hard to bind first one and then speeds up

• example of allosteric effect

Allosteric Effects

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CO

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• loses cooperativity

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MetHB

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• rest of Fe2 binds O2 with higher affinity, left shift curve

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• methylene blue reduces Fe3 to Fe2

• vitamin C reduces Fe3 to 2

• SOB from methemoblobinemia

• interferes with pulse ox

• normal amount of O2 in blood

CN

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• functional hypoxia: enough O2 around but can't use them

• inhibits cytochrome oxidase a3