Final answer:
Glycoprotein synthesis involves glycosyltransferases that enzymatically add sugars to proteins, occurring predominantly in the Golgi apparatus and resulting in glycoprotein formation crucial for cell membrane structure and function.
Step-by-step explanation:
The membrane-bound enzymes that transfer sugar residues to growing carbohydrate chains during glycoprotein synthesis are called glycosyltransferases. These enzymes catalyze the addition of sugar moieties to form glycosidic bonds, which are crucial in the synthesis of glycoproteins.
Glycosylation of proteins involves the enzymatic process where carbohydrates (sugars) are attached to proteins. This happens as proteins move through the Golgi apparatus of the cell's endomembrane system. As these proteins travel through the Golgi complex, glycosyltransferases add sugars to the growing glycan chains on the proteins, resulting in fully synthesized glycoproteins. Once the vesicles budding from the trans-Golgi fuse with the plasma membrane, the sugar-modified proteins are typically inserted into the plasma membrane and function in cell-cell recognition, signaling, and creating the glycocalyx.