2.12-Hemo&MyoGlobin Flashcards Preview

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Flashcards in 2.12-Hemo&MyoGlobin Deck (28):

What is the Bohr effect?

Effects of CO2 and H+ on HemoGlobin


Does cooperatively work in hemoglobin or myoglobin? Or both?

Hemoglobin only


What type of oxygen binding curve does Hemoglobin have? What Partial Pressure does it bind at?

Sigmoidal. Binds at 26 torr


What type of oxygen binding curve does Myoglobin have?



What is the structure of hemoglobin? hint: how many dimers..etc

Its a TETRAMER composed of two Alpha-Beta Dimers


What are the __3__ methods to get CO2 from the tissues to the lungs? Whats the major way?

Dissolved CO2 in blood, Carbamino-hemoglobin, and bicarb... Bicarb is MAJOR way, 14% Carbamate


What 3 signalers facilitate the release of oxygen from hemoglobin?

Increase H+, Increased CO2, and Increased 2,3BPG...Think cell that is working hard needs more O2!!


Which form of hemoglobin can be used to monitor long-term blood glucose control in diabetics?

Hemoglobin A1c


What is the RATE LIMITING step in Heme Synthesis? What is the enzyme used? What Coenzyme is used?

Succunyl-CoA + Glyceine = DALA.. Enzyme:DALA Synthase COenzyme: Pyridoxal phosphate DALA DALA BILLS YO


Where are the two main locations of Heme synthesis?

Bone marrow and liver


What type of rings comprise the active sight of heme and myoglobin? Which ion form of iron is in the center?

4 Pyrrole (5C) rings; Fe2+


What is myglobin made from? How many alpha helices? What keeps the O2 in?

One polypeptide chain and 8 alpha helices..A distal and a proximal histidine keep the oxygen in


When does myoglobin have the highest affinity for oxygen? What Partial Pressure?

At LOW [O2] (2 torr). Its like a sponge for muscle cells


What is the most common form of Hemoglobin in adults?

Hb A


What type of hemoglobin has a higher affinity for O2 and therefore is genetically stimulated for sickle cell anemia pts?

Hb F (Fetal hemoglobin)


Is hemoglobin considered hydrophilic or hydrophobic?

Hydrophobic, even though it has H bonds and ionic pairs!


Which formation has a LOW affinity for O2? T or R?

Taut (release oxygen)


Which formation has a HIGH affinity for O2? T or R?

Relaxed (pick up oxygen)


What is the degree of difference between T and R?

15 degrees


When oxygen binds to iron II does the active site go into the plane of the molecule or go out of the plane of the molecule?

It goes into the plane


Why would high 2,3BPG increase hemoglobin release of oxygen? Which state does it put hemoglobin in? R or T?

2,3BPG is a byproduct of glycolysis. The cell is working hard and needs oxygen. T=taut=low O2 affinity=release of O2


What about the structure of Fetal hemoglobin causes more O2 affinity? What about 2,3 BPG?

Because it has two alpha and two GAMMA subunits it does not bind 2,3 BPG as well. NO 2,3 BPG=NO T formation=Less release of O2


How much of a pH difference causes an 11% difference in O2 release?

7.4 to 7.2 pH causes hemoglobin to release 11% more O2


Does CO2 compete with O2 for binding sites on hemoglobin?



What is the protein produced by RBCs that binds to alpha-chains on hemoglobin?

AlphaHemoglobinStabilizingProtein (AHSP)


What is substituted for the normal glutamine on the Beta subunit for sickle cell anemia Pts? Does it affect deoxyhempglobin or oxyhemoglobin?

Valine causes mutancy, Affects deoxy but not oxy


What do cells put out that will increase the affinity for more O2?

2,3 BPG


Bohr effect?

effect of CO2 and Hydrogen Ions on O2 affinity