Biology Stack Exchange is a question and answer site for biology researchers, academics, and students. It only takes a minute to sign up.
Sign up to join this community
Let's say there are two diets, consisting of entirely different proteins. If you split up all of the proteins from one day of each diet, you'll get the same set of amino acids and the same count of each. Assume everything else about the diets is the same.
Would these diets have the same effect on the protein composition in your body? Different polypeptides, but overall the monomers are identical. Does your body break down proteins entirely, or will it reuse some chains of amino acids?
Arrangement of amino acids determines the protein structure which in turn can determine how easy it is to digest the protein. I cannot think of an example right now; never really checked if two entirely different proteins have identical composition. However, it is not really surprising. In chemistry, it is known that different isomers have vastly different physical properties.
So if the two proteins have different digestibility then they will have different nutritive values.
Regarding, protein digestion and nutrition. New proteins are built from individual amino acids and not pre-formed oligomers. Read about translation. So at some point the ingested protein has to be completely broken down into amino acids.
