Bohr effect - forward

[ArchivalUser]

A physician told a patient that she had no Bohr effect. What amino acids were missing in her hemoglobin?

A. carboxyl -terminal residues
B. heme binding ligands
C. proximal F8 His
D. B8 Glu
E. beta chain DPG binding residues

[ArchivalUser]

not sure..bohr effect mean co2 causes release of o2...basically shift of curve to right..this happens by H+binding to Hb displacing O2 ...so it should be a defect in binding of H+ to Hb...dont know what though

[ArchivalUser]

b?

[ArchivalUser]

I think the ans should be B. When the Hb goes around to the tissues, O2 is bound to its 4 binding sites. When it gets to the tissues where the PO2 is low, the O2 moves from an area of high PO2 to an area of low PO2 that is it moves off Hb and into the cells. This causes a conformational change in Hb whic exposes binding sites for CO2 . when CO2 binds this is now called carboxyhaemoglobin and that travels to the lungs. The bohr effect comes into play here because the PCO2 in the Blood going to the lungs is a bit higher that the PCO2 in the lung itself. Beside the lung has a high PO2. When this Hb with its load of Co2 reaches the lungs and encounters high PO2 there is a conformational change to expose the binding sites for O2 and because of this Co2 is dropped off to be exhaled by the Lungs!!!!!!!!!!!!

[ArchivalUser]

Is this has to do with Haldane efect from the fact that hemoglobin became a stonger acid when it combine with oxugen ?carboxull ?

[ArchivalUser]

iNCREASE ACIDITY OF HEMOGLOBIN DISPLACE carbon dioxide for the following reasons : the excees hydrogen ions realesed from hemoglobin bind with bicarbonate to form CARBONIC ACID.Th ecarbonic acid then dissocietes into water and CO2 and the crabon dioxide diffus efrom blood into the alveoli.
The second reason is that higly acidic hemoglobin has less tendency to bind with carbone dioxide to form carbaminohemoglobin.The carbon dioxide is thus displaced from its hemoglobin binding site allowing it to diffuse into the alveoli.
The Haldane effcet nearly double the amount of carbon dioxide released from the blood in th elung where the po2 IS HIGH, AN FNEARLY DOUBLE THE AMONT OF CARBON DIOXIDE PICKED UP BY BLODD IN THE TISSUES WHERE THE PO2 is low.


mOST OF THE EFFECT OF PCO2 known as Bohr effect can b eattributed to its action on PH.When the curve is shifthed to the rigth , the % saturation of hemoglobin is reduced at each value of PO2 i.e.P50 is increased.

What do you think ????????

[ArchivalUser]

yeah youre right i saw bohr and thought haldane..... funny how the brain works

[ArchivalUser]

forward!
what is the correct answer? and can you give the explanation too? Please!
When I posted a question I always give the answer at the end with the explanation. I don't understand why so many people just give the qs and not answers. It is supposed to be interactive, but I get so confused when everybody give the answers and there is not the responsible of the qs given the correct answer.

[ArchivalUser]

Under resting condition about 4 millilitars of carbon dioxide is transported from the tissue to the lungs in each 100 milliters of blood.
About 70 % of the crabone dioxide is transported to the lungs in the form of BICARBONATE IONS.
Disolved carbon dioxide reacts with water insid ethe red blood cells to form CARBONIC ACID.Th ereaction is catalyze by enzyme carbonic ahnhidrase.Most of the carbonic acid immediatelly dissocietes into bicarbonicate ions and hydrogen ions, the hydrogen ions in turn combine with hemoglobin.Aprox.23 % of the carbon dioxide produced in tissues combine sdirectelly with hemoglobin to form carbaminohemoglobin, and additional 7 % is transported in the dissolved state in eater of the plasma and cellsWhen blood arrives in the lungs, the carbon dioxide diffuses from theblood into the alveoli, causing rapid reversal of these chemical reactions.

[ArchivalUser]

b?