A researcher proposes a model to explain how enzyme-substrate interactions determine enzyme specificity. The model is based on the idea that substrate molecules form favorable interactions with the amino acid side chains in an enzyme’s active site. Based on the model, which of the following statements best explains an enzyme’s specificity for a particular substrate molecule?
a. A hydrophilic molecule interacts with nonpolar side chains in the enzyme’s active site. b. A hydrophobic molecule interacts with polar side chains in the enzyme’s active site. c. A molecule with positive charges interacts with positively charged side chains in the enzyme’s active site. d. A molecule with negative charges interacts with positively charged side chains in the enzyme’s active site.