Unit 3: Cellular Energetics

The region of the enzyme, formed by specific amino acid R groups, where the substrate binds and the reaction is catalyzed.

The active site's shape and chemical properties (charge, polarity) are complementary only to particular substrates.

Substrate binding causes the active site to change shape slightly, gripping the substrate more tightly and positioning it for reaction.

Lock-and-key treats the active site as rigid; induced fit recognizes that enzymes are flexible and change conformation when substrate binds.

The active site can be lined with positively charged R groups (e.g., lysine, arginine) that attract it electrostatically.

The substitution can change how the protein folds, which can distort the active site's shape.