IB Biology Exam Prep

Answer: D, Lipase. Lipase is an enzyme, and enzymes do not form larger structures.

Key Takeaway: A key characteristic of life is that smaller subunits combine to form larger, more complex structures. Amino acids combine to form proteins, nitrogenous bases combine with sugars to form nucleosides, and simple sugars combine to form complex sugars. An enzyme is already arranged as a complex structure, and will not combine to form a larger structure.