AP BIOLOGY

Detailed explanation-1: -The endoplasmic reticulum (ER) is a membranous organelle that shares part of its membrane with that of the nucleus. Some portions of the ER, known as the rough ER, are studded with ribosomes and are involved with protein manufacture.

Detailed explanation-2: -The Golgi apparatus, or Golgi complex, functions as a factory in which proteins received from the ER are further processed and sorted for transport to their eventual destinations: lysosomes, the plasma membrane, or secretion. In addition, as noted earlier, glycolipids and sphingomyelin are synthesized within the Golgi.

Detailed explanation-3: -The ER has a central role in lipid and protein biosynthesis. Its membrane is the site of production of all the transmembrane proteins and lipids for most of the cell’s organelles, including the ER itself, the Golgi apparatus, lysosomes, endosomes, secretory vesicles, and the plasma membrane.

Detailed explanation-4: -The correct answer: The cellular organelle which functions as the synthesis site of secreted and membrane proteins is rough endoplasmic reticulum.

Detailed explanation-5: -The three primary functions of the Golgi apparatus are the transport, sorting and modification of both protein and lipid, and the protein composition of the organelle reflects these functions.