Site MapHelpFeedbackHemoglobin Causes Net Diffusion of Oxygen
Hemoglobin Causes Net Diffusion of Oxygen

Why is the reduction in the oxygen pressure due to hemoglobin biologically important? Gas exchange is a cycle. Oxygen diffuses into the blood stream, is transported to cells and diffuses into the cells. Carbon dioxide does the same thing in reverse. The rate of diffusion is key to the efficiency of gas exchange. The rate of diffusion depends on the concentration gradient. The greater the difference is gas concentration across a membrane, the more rapidly the gas will diffuse. However, the very act of diffusion will reduce the gradient. By taking gases out of solution in the blood hemoglobin maintains concentration gradients and a continuous diffusion of oxygen and carbon dioxide.

View the animation below, then complete the quiz to test your knowledge of the concept.






1In this animation, when the hemoglobin molecules become saturated with oxygen molecules...
A)equilibrium is unattainable between the two sides of the oxygen-permeable membrane due to the repulsion of the free oxygen molecules by the saturated hemoglobin molecules.
B)equilibrium is unattainable between the two sides of the oxygen-permeable membrane due to the affinity of the free oxygen molecules for the hemoglobin molecules.
C)the area on the side of the oxygen-permeable membrane without the hemoglobin maintains more free oxygen molecules than the other side.
D)the area on the side of the oxygen-permeable membrane with the hemoglobin maintains more free oxygen molecules than the other side.
E)the oxygen molecules in the area on both sides of the oxygen-permeable membrane reach equilibrium.



2How many oxygen molecules can each hemoglobin molecule transport?
A)two
B)four
C)six
D)eight
E)ten



3When the water on one side of the semipermeable membrane contains hemoglobin molecules and the water on the other side does not...
A)the Po2 will eventually equalize after the hemoglobin molecules become saturated with oxygen.
B)the Po2 will be unable to equalize after the hemoglobin molecules become saturated with oxygen because of the attraction between oxygen and hemoglobin.
C)the area on the side of the oxygen-permeable membrane with the hemoglobin maintains a higher Po2.
D)the area on the side of the oxygen-permeable membrane without the hemoglobin maintains a higher Po2.
E)the Po2 will be unable to equalize after the hemoglobin molecules become saturated with oxygen because of the repulsion between oxygen and saturated hemoglobin.



4Oxygen’s great affinity for hemoglobin molecules causes oxygen molecules to diffuse from the lungs to the capillaries.
A)True
B)False



5Oxygen’s diffusion from the lungs to the blood ceases as the hemoglobin molecules become saturated with the oxygen molecules.
A)True
B)False







Animation Quiz SiteOnline Learning Center

Home > Biology 1 > Chapter 42 > Hemoglobin Causes Net Diffusion of Oxygen