Between glycation and glycosylation, the main difference is that glycation cannot be enzymatic while glycosylation can.Sugar molecules are added to proteins via glycation and glycosylation. Glycation occurs spontaneously in the bloodstream and is a non-enzymatic process of adding free sugars to proteins in a covalent way. The glycosylation process takes place within the endoplasmic reticulum and the Golgi apparatus after a protein has been translated and is ready for use. Although glycation and glycosylation have some similarities, this article focuses on the differences between the two.