The process of protein synthesis and secretion starts from the endoplasmic reticulum. The polypeptide chain is formed in the ribosomes, and then transferred to the Golgi apparatus, where the final modifications are done. The Golgi apparatus sorts the modified poly peptide molecules and packages into new transport vesicles which reach their particular destinations. The tranlocons transport the polypeptides with a signal sequence to the interior of the endoplasmic reticulum. Multiple control mechanisms of the endoplasmic reticulum ensures that only properly folded proteins to export towards the Golgi apparatus. The plasma membrane proteins synthesized in the endoplasmic reticulum (ER). The proteins generally contain endoplasmic reticulum signal sequence at their N-terminus, which directs them to the rough endoplasmic reticulum. After completion of translation process in the RER, the polypeptide chains get inserted into the ER membrane or into the lumen of ER. Some proteins move to the transport vesicles, which fuse together to form cis- Golgi vesicles, the cis-form again moves to trans-form. During this process, many proteins undergo modifications particularly at oligosaccharide chains. From the trans-Golgi vesicles, proteins move to cell membrane through small transportation vesicles (exocytosis). Solution The process of protein synthesis and secretion starts from the endoplasmic reticulum. The polypeptide chain is formed in the ribosomes, and then transferred to the Golgi apparatus, where the final modifications are done. The Golgi apparatus sorts the modified poly peptide molecules and packages into new transport vesicles which reach their particular destinations. The tranlocons transport the polypeptides with a signal sequence to the interior of the endoplasmic reticulum. Multiple control mechanisms of the endoplasmic reticulum ensures that only properly folded proteins to export towards the Golgi apparatus. The plasma membrane proteins synthesized in the endoplasmic reticulum (ER). The proteins generally contain endoplasmic reticulum signal sequence at their N-terminus, which directs them to the rough endoplasmic reticulum. After completion of translation process in the RER, the polypeptide chains get inserted into the ER membrane or into the lumen of ER. Some proteins move to the transport vesicles, which fuse together to form cis- Golgi vesicles, the cis-form again moves to trans-form. During this process, many proteins undergo modifications particularly at oligosaccharide chains. From the trans-Golgi vesicles, proteins move to cell membrane through small transportation vesicles (exocytosis)..