respiratory acidosis/alkalosis Acid–base homeostasis

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Oh_Gee

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I'm having trouble understanding how this works. So if too much CO2 is expelled then you get respiratory alkalosis (hyperventilation) and if there's a build up of CO2 (hypo ventilation), then you get respiratory acidosis. Why is this??? H+ and HCO3- are in a 1 to 1 ratio so if, say, you have a case of hypo ventilation, then why isn't there an equal increase in both [H+] and [HCO3-]?

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We can use Le Chatelier's Principle to figure out this question:
During hyperventilation, the amount of CO2 is diminishing (lower [CO2]), according to La Chatelier's the reaction will shift left to replenish CO2, reestablishing equilibrium, during the process more H+ is used up leading to a higher pH or lower pOH, this leads to alkalosis.
During hypoventilation, the amount of CO2 is building up (high [CO2]), to compensate for this change, the reaction will shift to the right to make more H+, thus lowering the pH leading to acidosis.
 
We can use Le Chatelier's Principle to figure out this question:
During hyperventilation, the amount of CO2 is diminishing (lower [CO2]), according to La Chatelier's the reaction will shift left to replenish CO2, reestablishing equilibrium, during the process more H+ is used up leading to a higher pH or lower pOH, this leads to alkalosis.
During hypoventilation, the amount of CO2 is building up (high [CO2]), to compensate for this change, the reaction will shift to the right to make more H+, thus lowering the pH leading to acidosis.

well for example, hypoventilation,:how come that if it shifts to the right, [HCO3-] isn't affected as well?
 
Think of it in terms of Le Châtelier's Principle. In hyperventilation, lots of CO2 is being lost. The body compensates by shifting the equilibrium to make more CO2, which results in less available free H+, raising the pH of the blood. In hypoventilation, lots of CO2 is being retained, so the equilibrium will shift to the right to compensate, forming more H+ and lowering the pH of the blood. Even though the ratio of hydrogen ion and bicarbonate is 1:1, pH is a measure of the hydrogen ion concentration, the bicarbonate ion doesn't matter with respect to the pH value.
 
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We can use Le Chatelier's Principle to figure out this question:
During hyperventilation, the amount of CO2 is diminishing (lower [CO2]), according to La Chatelier's the reaction will shift left to replenish CO2, reestablishing equilibrium, during the process more H+ is used up leading to a higher pH or lower pOH, this leads to alkalosis.
During hypoventilation, the amount of CO2 is building up (high [CO2]), to compensate for this change, the reaction will shift to the right to make more H+, thus lowering the pH leading to acidosis.

Phone didn't load your comment til after I replied. Pretty much repeated what you said lol
 
well for example, hypoventilation,:how come that if it shifts to the right, [HCO3-] isn't affected as well?
Its [] would also increase but HCO3- is amphoteric, you're mainly concerned with [H+] at this point because influx of pH in the blood (normally about 7.4) can be deadly.
 
Think of it in terms of Le Châtelier's Principle. In hyperventilation, lots of CO2 is being lost. The body compensates by shifting the equilibrium to make more CO2, which results in less available free H+, raising the pH of the blood. In hypoventilation, lots of CO2 is being retained, so the equilibrium will shift to the right to compensate, forming more H+ and lowering the pH of the blood. Even though the ratio of hydrogen ion and bicarbonate is 1:1, pH is a measure of the hydrogen ion concentration, the bicarbonate ion doesn't matter with respect to the pH value.
touché
 
so i should only consider [H+] when the amount of CO2 is altered? is there ever a case where [HCO3-] should be considered?
 
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