If one amino acid is a protein sequence is changed what could happen

Proteins are so complex that one amino acid won't make a difference.

The correct answer is that a completely different protein will be synthesized. Proteins are made out of long chains of amino acids. There's 500 + of them but only 20 or so are used for humans. They have infinite amounts of combinations and each combination synthesizes a different protein. Our body knows what it needs so it synthesizes it from food that we take.