system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If proteins get denatured by extreme acidic or alkaline environments, how does it survive our stomach acid and go into the small intestine for digestion without any harm?
gpt
In simple terms, it doesn't. The aim of digestion isn't to take in whole proteins from food, but to break them down into their 'building block' parts, called amino acids. Protein digestion begind in the stomach, in which ingested proteins are denatured by the acid. However, their breakdown is also accelerated by pepsin enzymes (which are produced in the stomach and work optimally in the acidic environment). By the time your ingested protein is absorbed in the intestine (after undergoing further breakdown by enzymes secreted by the pancreas) it exists as a 'pool' of amino acids which can then be utilised as the building blocks for other proteins your body needs.