O2 and CO2 Gas Transport Flashcards
Gases dissolve in liquids by amounts that are directly proportional to…
their partial pressure
Gases that are less soluble…
What increases the solubility of O2 in blood?
Hemoglobin helps increase the oxygen content in blood
Describe hemoglobin
- 4 polypeptide globin chains
- each globin chain is associated with an iron-containing heme group
- O2 molecules can bind reversibly to each of the heme groups
Why does O2 have to bind reversibly to hemoglobin?
As blood becomes oxygenated, it shifts from…
blue to red (changes the absorption spectrum of blood)
Total blood content = oxygen bound to hemoglobin + dissolved oxygen
Oxygen content calculation formulas!
** do the practice problem!
Understand the O2 dissociatio curve
- S-shaped curve (not a linear relationship)
- Partial pressure of oxygen in venous blood is around 40
- Partial pressure of oxygen in arterial blood is around 100
- The flat part of the curve?
- The steep part of the curve?
Why is carbon monoxide (CO) poisonous?
It has the same hemoglobin binding sites as oxygen, but it has a much higher affinity for hemoglobin than oxygen, so it will bind at a significantly lower partial pressure and interfere with O2 binding. Once it is bound, it also alters the binding affinity of Hb for O2, resulting in impaired release to tissues.
How do we treat carbon monoxide poisoning?
CO2 is transported in blood in three forms…
- bicarbonate (most important)
- dissolved CO2 (plasma)
- carbamino compounds bound to Hb
What is the reaction for converting CO2 to bicarbonate in the blood?
Where is most of the bicarbonate made?
Within the RBC
Describe the difference between O2 and CO2 content curves
There is a much more linear relationship between CO2 partial pressure and CO2 concentration in the blood.
