Final answer:
The process of covalently attaching a carbohydrate to a lipid or protein is called glycosylation, a fundamental biological process important for cell functions.
Step-by-step explanation:
The process of covalently attaching a carbohydrate to a lipid or protein is known as glycosylation. This biological process is crucial for the formation of glycoproteins and glycolipids, which play significant roles in cell-cell recognition, signaling, and the immune response. Glycosylation occurs in the endoplasmic reticulum and the Golgi apparatus as enzymes add sugars to proteins and lipids, creating complex structures that facilitate various biological functions.