Proteins and lipids synthesized in the endoplasmic reticulum (ER) are transported to the Golgi apparatus in vesicles. Once they reach the Golgi, they enter the cis face, which is the side of the Golgi apparatus facing the ER. As molecules pass through the cisternae from the cis face to the trans face, they undergo various modifications. Glycosylation, phosphorylation, and sulfation are some of the common modifications that occur in the Golgi.
