BIO 3302 Lecture Notes - Lecture 6: Blood Doping, Bohr Effect, Nfkb1
13 Dec 2016
School
Department
Course
Professor
LECTURE 6 – BLOOD GAS TRANSPORT
Discuss in groups
• Sketch an o2 eq curve for abnormal human and one that has taken EPO or used blood doping
to increase blood O2 carrying capacity
o Why is EPO or blood doping dangerous?
o Input more RBC's so there is more blood circulating to tissues
Impt bc partial pressure is the same even if more RBC's are present
Allosteric modulators of O2
• As you add O or protons to blood hemoglobin affinity for O2 falls
• Add protons, right shift of eq occurs, p50 goes in, CO2 goes down
• BOHR EFFECT
o Tissues are in an area where CO2 is added to blood and lowers affinity for hemoglobin
to O2 so that its easier for O2 to enhance O2 to be released from blood and into tissues
by gas exchange
• cO2 being lowered and curve shifts back to left so that affinity is increase and o2
is easier loaded into hemoglobin at respiratory surfaces. (lung or gill)
• Temperature
o Increase in temp lowers affinity for hemoglobin for O
o Shift curve to left and affinity goes up - benefits O2 unloading into the tissues
• Working muscles generating heat and addition of CO2 triggers Bohr effect and
heat triggers curve to left - hard working muscles get more O
o Prob for ectothermic animal - fish amphibian reptiles
• Whole body of animal becomes warm you can still get right shift which lowers
affinity for hemoglobin to O - not as easy to unload blood to tissues
• Metabolic rate depends on temp for ectotherms
• Ability to deliver said O is lower - not as capable of loading O into blood.
• Solubility of O is lower as T goes up - but animal needs more O bc of higher
metabolic rate
• Organic phosphates conc in blood cells
o Mammals - 2,3biphosphoglycerate (DPG)
o Birds - inositol pentaphosphate (PIP)
o High organic phosphate levels shift curve to right - lower affinity for O
o Effects if organic phosphates is a slower reaction bc takes time to change conc levels
o EX Fish under chronic hypoxia - organic phosphate levels fall - harder to synthesize ATP
when phosphate levels fall and so P50 levels fall and shift left to increase affinity of
hemo for O
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Input more rbc"s so there is more blood circulating to tissues. Impt bc partial pressure is the same even if more rbc"s are present. Right shift = higher 23 dpg, left shift = hyperventilation triggering bohr effect: bohr effects shifts curve to left to benefit o unloading. If human stays on mt everest for weeks it will trigger epo causing more rbc to be made. Speeds up rxn - more co2 enters rbc: minor contributor vo2+h20 -> h+ + hco3. Curved lines show relationship between cco2 content and pco2 in blood. Co2 in blood is result of capacitance of co2. Deoxy blood holds more co2 than oxy blood bc deoxy hemo has more h+ than deoxy hemo. Allows more co2 to be loaded into blood. Mirror image of bohr effect which describes proton binding on oxygenation status. B:shifts to right or left as change protons levels affinity for hemoglobin for o changes.
