Which of these statements does NOT describe HCO₃- excretion by the kidneys
A)During HCO₃- reabsorption, HCO₃- in the tubular fluid is actively cotransported by K⁺.
B)HCO₃- is not excreted at pH = 7.4.
C)Secretion of H⁺ is accompanied by the addition of new HCO₃- to the plasma.
D)Excretion of HCO₃- increases during alkalosis.

Question

Quizplus · Accepted Answer

During HCO₃- reabsorption in the kidneys, HCO₃- in the tubular fluid is not actively cotransported with K⁺. Instead, it involves the conversion of HCO₃- to CO₂ within the tubular cells, which then diffuses into the cells to be converted back into HCO₃-. This process is primarily facilitated by the enzyme carbonic anhydrase and involves the exchange of H⁺ ions into the tubular fluid, not K⁺.

Which of These Statements Does NOT Describe HCO₃- Excretion by the Kidneys