@Nietzsche said in How does CO2 actually increase respiration?:

It seems to me that adding CO2 to a system should shift the respiration reaction AWAY from CO2 due to Le Chatelier’s principle. Does Peat ever address this? Does it not work this way in the body?

Le Chatelier's Principle states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium moves to counteract the change. In the context of respiration in the human body, the reaction you're referring to is likely the production of carbon dioxide (CO2) as a byproduct of cellular respiration.

According to Le Chatelier’s Principle, adding more CO2 to the system would indeed be expected to shift the equilibrium to the left, reducing the formation of CO2. However, in living organisms, things are more complex due to several reasons:

A: The human body is an open system, constantly exchanging matter and energy with its environment. This means CO2 is continually removed from the body (through exhaling), preventing the accumulation that would shift the equilibrium significantly.

B: Enzymes in the body regulate metabolic pathways, including respiration. These enzymes can alter the rate of reaction in response to various factors, and their activity is not solely dictated by the concentrations of reactants and products as in a simple chemical equilibrium.

C; The body has buffer systems, especially in the blood, to maintain pH balance. These systems can absorb or release CO2 and H+ ions, mitigating the effects of changes in CO2 concentration.

I think Peat mentioned Le Chatelier's book.