9.2 Gas Exchange and Transport Flashcards
What is partial pressure?
Partial pressure is the amount of pressure a gas exerts. Dalton’s Law of partial pressure states: each gas exerts it’s own pressure.
- Partial Pressure of O2: Changes in the body, is very high in atmosphere, medium in blood, and low in tissues. Therefore, O2 diffuses in.
-Partial Pressure of CO2: Changes in the body, is very high in tissues and blood, medium in alveoli, and low in the atmosphere. Therefore, CO2 diffuses out.
What does gas exchange rely on?
Gas exchange relies on hemoglobins which are found on the surface of the RBC. They are made of polypeptides, and contain a heme portion (iron containing) and globin protein portion.
What are the steps in oxygen exchange?
The steps in oxygen exchange include:
1. O2 diffuses into blood through capillaries outside the alveoli.
2. The O2 binds with hemoglobin to form oxyhemoglobin.
3. O2 is dislodges by H+ions.
4. O2 diffuses into cells.
What are the steps in carbon dioxide exchange?
The steps in carbon dioxide exchange include:
1. CO2 diffuse out of cells into the blood.
2. It is transported to the lungs two ways: with hemoglobin or in plasma.
- With hemoglobin, it combines with the hemoglobin and is transported to the lungs as carbaminohemoglobin.
- In plasma, it combines with H2O in plasma to form carbonic acid. The carbonic acid dissociates to form a hydrogen ion and bicarbonate ion. The bicarbonate ions are transported to the lungs in plasma. The H+ions dislodge O2 from hemoglobin, and bind with the hemoglobin to act as a buffer (a substance that is able to neutralize acids and bases).
3. At the lungs, H+ dislodges from hemoglobin and combines with bicarbonate ions. CO2 and H2O diffuses from the capillaries in the alveoli into the lungs and is exhaled.
