Answer
Hydrogen bonds are most important for hydrophobic macromolecules: carbohydrates, nucleic acids, and proteins. In contrast, hydrophobic interactions are most critical for lipids, which are mostly hydrophobic and which form the hydrophobic membranes which separate parts of cells from one another. However, lipids still do have hydrogen bonds with water at their head groups, and proteins and carbohydrates can have hydrophobic regions based on their 3D structure.
Work Step by Step
To answer, consider each macromolecule in turn and ask: does it most interact with water (hydrogen bonds critical) or flee water (hydrophobic interactions). Summarize, but then go back and list partial exceptions like the water-interacting head groups of lipids.
