Question

how does increasing and decreasing levels of PCO2 relate to increasing of decreasing levels of HCO3 and H+

Answer 1

Increasing level of PCO2 causes acidosis by decreasing H+ ion in the body which decreases the pH. Decreasing the level of PCO2 can cause alkalosis by increasing H+ ion in the body which increases pH.

It means increased in the PCO2 level decreases the pH and causes acidosis, to compensate this acidosis(Means,to bring pH into normal level or in other words to decrease H+ ion in the body) the body tries to increase HCO3 level by different mechanisms.

Decreased in the PCO2 level increases the pH and causes alkalosis, to compensate alkalosis(Means, to bring pH into normal level or in other words to increase H+ ion in the body) the body tries to decrease HCO3 level by different mechanisms.