How do amino acids affect enzymes?

Typically, enzymes are proteins that catalyze a reaction toward a target.

Since the enzyme is made of proteins, amino acids have no effect on it other than on how the enzyme is made (unless the enzyme is part of a reaction that requires amino acids in some way).

Saying something like "Lego pieces are used to make the Lego DeathStar - how do Lego pieces affect the Lego DeathStar?" is analogous to this.

The way in which amino acids contribute to the formation of an enzyme's active site—where the substrate binds and the chemical reaction takes place—determines the specificity and catalytic activity of the enzyme. In addition, some amino acids within the enzyme can function as catalytic residues, directly engaging in the chemical reaction. Finally, changes in pH and temperature can modify the structure and charge of amino acids within the enzyme, thereby impacting its activity.