CO2 transport

Question 1

____% CO2 physically dissolved

Answer 1

10%

Question 2

____% CO2 bound to Hg (carbamino hemoglobin, HbCO2) at ______ portion not at heme portion

Answer 2

30%

globin

Question 3

____ % bound to Hg (carbamino hemoglobin, HbCO2) at _____ portion not at heme portion

Answer 3

30

globin

Question 4

60% as

Answer 4

bicarbonate (HCO3-)

Question 5

Carbonic anhydrase (HCO3-) exchanged by

Answer 5

chloride Cl-

Question 6

Carbon dioxide transport in the blood.

Answer 6

Carbon dioxide (CO2) picked up at the tissue level is transported in the blood to the lungs in three ways: (1) physically dissolved, (2) bound to hemoglobin (Hb), and (3) as bicarbonate ion (HCO3−). Hemoglobin is present only in the red blood cells, as is carbonic anhydrase, the enzyme that catalyzes the production of HCO3−. The H+ generated during the production of HCO3− also binds to Hb. Bicarbonate moves by facilitated diffusion down its concentration gradient out of the red blood cell into the plasma, and chloride (Cl−) moves by means of the same passive carrier into the red blood cell down the electrical gradient created by the outward diffusion of HCO3−. The reactions that occur at the tissue level are reversed at the pulmonary level, where CO2 diffuses out of the blood to enter the alveoli.