Question

The chloride shift

Multiple Choice

• maintains the ionic balance between the red blood cells and the plasma.

• inflates alveoli while decreasing oxygen delivery to tissues.

• replaces carbonic anhydrase.

• regulates the amount of salt in the large intestine compared to the small intestine.

• maintains blood pH

Answer 1

maintains the ionic balance between the red blood cells and the plasma.

explanation: Carbon dioxide diffuse into the red blood cells where they combine with water and forms carbonic acid which then dissociates to form bicarbonate and hydrogen ion. If too much H+ is produced, it can alter blood pH. However, hemoglobin binds to the free H+ ions and thus limits shifts in pH. The newly synthesized bicarbonate ion is transported out of the red blood cell into the liquid component of the blood in exchange for a chloride ion (Cl−); this is called the chloride shift. This maintains the ionic balance.