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aTacoParty t1_j9axl9r wrote

The name amino acid refers to the amine group (NH2-R) and the carboxylic acid group (COOH-R) that make up the backbone of amino acids. The amine group can be a proton acceptor while the carboxylic group can be a proton donator so most amino acids are neutral. Some amino acids have acidic R groups (gutamate/asparatate) which makes them acidic, while others have basic R groups (lysine, histidine, arginine) which makes them basic.

In reality, since proteins are made up of 100's or 1000's of amino acids, they act as buffers, accepting and donating protons as needed in the blood. However, protein isn't the main buffer used to maintain the blood pH. Our bodies need blood to be kept at ~7.4 pH in order to function and if that changes too much we can get really sick. Our blood uses carbonic acid/bicarbonate as its main buffer which provides stability to the blood pH.

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stronkreddituser OP t1_j9ayzil wrote

So, from my understanding of what you wrote, amino acids have both basic and acidic properties due to the presence of a basic amine and an acidic COOH as functional groups (other than the variable R group)... Although it is ultimately the buffers in our blood that are largely responsible for maintaining a pH of ~7.4.

Thanks for the detailed explanation!!

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aTacoParty t1_j9b2454 wrote

100% correct!

And since carbonic acid/bicarb is the main buffer in blood, we regulate that by regulating our breathing. CO2 is converted into carbonic acid so by holding our breath (or breathing slower), we retain CO2 and decrease blood pH. Inversely, by breathing faster we blow out more CO2 and increase our blood pH.

Decreased blood pH is one of the main drivers for breathing. When you're swimming underwater and you start to feel the urge to breathe, it isn't lack of oxygen but rather the decreased blood pH from retained CO2 that your brain is sensing.

As a short aside, it's really bad for your blood to be more acidic OR more basic than ~7.4 pH. So when you see products claiming to "alkalinize" your body/blood for health, it's complete BS. Acids and bases are not inherently bad or good just like how hot and cold things are not inherently bad or good. I see these ads pop up pretty frequently, especially in fitness related settings and it drives me nuts.

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