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29 Cards in this Set
- Front
- Back
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components of the hemoglobin molecule
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2 alpha chains
2 non-alpha chains 2 heme molecules |
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Heme
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- protoporphyrin IX
- atom of divalent/ferrous iron (Fe2+) |
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What makes blood red?
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heme
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How many heme groups are there per chain?
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1
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How many amino acids are in each globin chain?
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~140 amino acids
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Which globin chains are on chromosome 16?
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alpha
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Which globin chains are on chromosome 11?
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beta
delta gamma |
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Which genes have 2 copies per chromatid (4 genes total)?
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alpha
gamma |
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What are the steps of hemoglobin formation?
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1. globin genes get transcribed to mRNA
2. mRNA is translated to a globin polypeptide chain and released in cytoplasm 3. globin chains bind to heme 4. heterodimers form between alpha and non-alpha chains 5. tetramers form |
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Hemoglobin A
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- 2 alpha chains and 2 beta chains
- The main form of hemoglobin after birth |
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Hemoglobin A2
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- 2 alpha chains and 2 delta chains
- Delta chains are not expressed efficiently - Normally only a small amount of Hb A2 after birth |
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Hemoglobin F
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- 2 alpha chains and 2 gamma chains
- In adults, this is only in a few RBCs, called F cells |
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Which hemoglobin chains can undergo post-translational modification?
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Hemoglobin A
Reactions can occur with various sugars and the amino groups of the globin chains Results in glycated hemoglobin Most common is Hb A1c, where glucose is added to the beta chain |
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How long is the lifespan of RBC?
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120 days
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Hemoglobin Function
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Bind oxygen in the lungs
Transport it to tissues Unload oxygen in the tissues |
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What is the partial pressure of oxygen at P50 for normal people?
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27 mmHg
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Bohr effect
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a shift of the curve as a result of pH
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What shifts the hemoglobin curve to the right?
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low pH (acidic, high H+)
high 2,3-BPG high Pco2 high temp Hb variants with low oxygen affinity |
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What shifts the hemoglobin curve to the left?
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Hb F
Hb variants with high oxygen affinity low temp low 2,3-BPG low Pco2 high pH (basic, low H+) |
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How does 2,3-bisphosphoglycerate (2,3-BPG) effect hemoglobin?
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with 2,3-BPG: tense and deoxygenated
without 2,3-BPG: relaxed and oxyenated |
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Why do newborns have higher Hb values than when they’re older (and have Hb A)?
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so that they can steal oxygen from mom
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HbF p50
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~20 mmHg
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RBC Metabolism
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- Can’t synthesize proteins or lipids
- Can’t undergo oxidative phosphorylation - Oxygen delivery process does not require energy consumption |
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What is the Embden-Meyerhof pathway?
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Glycolysis
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In glycolysis what does glucoes become?
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lactic acid
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Energy of glycolysis?
put in? taken out? net? |
put in: 2 ATP
taken out: 4 ATP net: 2 ATP |
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What pathway makes 2,3-BPG?
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Rapeport-Luebering Pathway
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What happens during the Methemoglobin reductase pathway?
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the methemoglobin is changed to hemoglobin
* important because methemoglobin is not fxnal |
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What is the importance of HMP shunt pathway?
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production of NADPH to have glutathione reductase and eliminate H2O2
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