Here's a breakdown:

* Proteins are long chains of amino acids linked together.

* Pre-digestion involves breaking these chains into smaller pieces. This is typically done by enzymes like pepsin (in the stomach) and proteases (in the small intestine).

* Peptides are shorter chains of amino acids, consisting of a few amino acids linked together.

* Amino acids are the individual building blocks of proteins.

Therefore, pre-digesting protein essentially makes it easier for the body to absorb and utilize the amino acids for various functions.