Lactate and lactic acid are essentially the same molecule, differing only by the presence or absence of a single proton (hydrogen ion).
Here's a more detailed breakdown:
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Lactic Acid: This molecule has a hydrogen ion (H+) that it can donate. This is what makes it an acid – its ability to release a proton.
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Lactate: This is what lactic acid becomes after it has donated its hydrogen ion. It's the conjugate base of lactic acid.
In biological systems (like the human body), lactic acid readily loses its hydrogen ion due to the neutral pH. Therefore, lactate is the predominant form found in the body, not lactic acid. While the terms are often used interchangeably, technically, lactate is more accurate when referring to the molecule present in biological contexts. The conversion is written as follows:
Lactic Acid ⇌ Lactate + H+
Think of it this way: lactic acid is the active form able to donate a proton; once it does, it becomes lactate.
