What you've described is called Plasticity
Also known as neuroplasticity or neural plasticity, it is a term used for the brain's ability to change itself and mold, like plastic, even in adulthood and when fully developed. This occurs for various reasons, not only due to physical damage.
When oxygenated blood is not delivered in a timely manner, the tissue will start to malfunction. oxygenated blood not delivered on time may be caused by hypoventilation, which is very dangerous and lethal. which will also result to high concentration carbon dioxide of the body
Unlike would fossil fuel burn without releasing energy
The pH will decrease because lemon juice is very acidic meaning it would bring the pH level down to a more acidic value.