Final answer:
Carbohydrates combine with proteins to make compounds found in the cell membrane.
Step-by-step explanation:
The type of macromolecule that combines with proteins to make compounds such as peptidoglycan and other identifying compounds found in the cell membrane is carbohydrates. Carbohydrates are bound to proteins (forming glycoproteins) or to lipids (forming glycolipids) on the cell's exterior surface. These glycoprotein and glycolipid complexes extend out from the cell surface and play a role in cell recognition and communication.