Properties of Enzymes

Steps:

• Statement 1 is false: Enzymes catalyze both breakdown (catabolism) and synthesis (anabolism) reactions, not just breakdown.
• Statement 2 is false: Many enzymes function extracellularly, such as digestive enzymes in the gut.
• Statement 3 is true: All enzymes form temporary enzyme-substrate complexes at their active sites.
• Statement 4 is true: As proteins, all enzymes have a specific tertiary structure enabling their catalytic function.

Why D is correct:

• Enzymes, being globular proteins, universally exhibit tertiary structure for shape-specific active sites and form temporary bonds with substrates per the lock-and-key or induced-fit model.

Why the others are wrong:

• A includes false statement 1.
• B includes false statement 1.
• C includes false statement 2.

Final answer: D