Physiology: The Respiratory System

Carbaminohemoglobin

bound form of hemoglobin and carbon dioxide

Bohr effect

relationship between blood pH and oxygen dissociation from hemoglobin

Compare and contrast adult hemoglobin and fetal hemoglobin.

Both adult and fetal hemoglobin transport oxygen via iron molecules. However, fetal hemoglobin has about a 20-fold greater affinity for oxygen than does adult hemoglobin. This is due to a difference in structure; fetal hemoglobin has two subunits that have a slightly different structure than the subunits of adult hemoglobin.

Describe three ways in which carbon dioxide can be transported.

Carbon dioxide can be transported by three mechanisms: dissolved in plasma, as bicarbonate, or as carbaminohemoglobin. Dissolved in plasma, carbon dioxide molecules simply diffuse into the blood from the tissues. Bicarbonate is created by a chemical reaction that occurs mostly in erythrocytes, joining carbon dioxide and water by carbonic anhydrase, producing carbonic acid, which breaks down into bicarbonate and hydrogen ions. Carbaminohemoglobin is the bound form of hemoglobin and carbon dioxide.

Describe the relationship between the partial pressure of oxygen and the binding of oxygen to hemoglobin.

The relationship between the partial pressure of oxygen and the binding of hemoglobin to oxygen is described by the oxygen-hemoglobin saturation/dissociation curve. As the partial pressure of oxygen increases, the number of oxygen molecules bound by hemoglobin increases, thereby increasing the saturation of hemoglobin.

A low partial pressure of oxygen promotes hemoglobin binding to carbon dioxide. This is an example of the ________. a) Haldane effect b) Bohr effect c) Dalton's law d) Henry's law

a) Haldane effect

Which of the following factors play a role in the oxygen-hemoglobin saturation/dissociation curve? a) temperature b) pH c) BPG

all of the above

Which of the following occurs during the chloride shift? a) Chloride is removed from the erythrocyte. b) Chloride is exchanged for bicarbonate. c) Bicarbonate is removed from the erythrocyte. d) Bicarbonate is removed from the blood.

b) Chloride is exchanged for bicarbonate.

Oxyhemoglobin forms by a chemical reaction between which of the following? a) hemoglobin and carbon dioxide b) carbonic anhydrase and carbon dioxide c) hemoglobin and oxygen d) carbonic anhydrase and oxygen

c) hemoglobin and oxygen

Carbonic Anhydrase (CA)

enzyme that catalyzes the reaction that causes carbon dioxide and water to form carbonic acid

Chloride Shift

facilitated diffusion that exchanges bicarbonate (HCO3-) with chloride (Cl-) ions