Proteins are first digested by the enzyme pepsin in the stomach where the pH is 2. Then in the small intestines where the pH is 8, the digestion of the protein is continued by trypsin and chymotrypsin. If pepsin was to move into the small intestine, how would its structure and function change? Pepsin will not change and will continue to breakdown proteins in the small intestines.
Pepsin will not change shape; it will adapt to the basic environment and continue to digest the proteins.
The basic environment of the small intestines would change the shape of pepsin and decrease its enzymatic activity.
Trypsin and chymotrypsin will change the shape of pepsin by acting as competitive inhibitors.