AP BIOLOGY

Detailed explanation-1: -The synthesis of proteins and lipids takes place in the endoplasmic reticulum. It is of two types-smooth endoplasmic reticulum (SER) and rough endoplasmic reticulum (RER). The lipid synthesis occurs in the smooth endoplasmic reticulum (SER).

Detailed explanation-2: -The organelle called ‘endoplasmic reticulum’ occurs in both plants and animals and is a very important manufacturing site for lipids (fats) and many proteins. Many of these products are made for and exported to other organelles.

Detailed explanation-3: -The endoplasmic reticulum is also part of a protein sorting pathway. It is, in essence, the transportation system of the eukaryotic cell. The majority of its resident proteins are retained within it through a retention motif.

Detailed explanation-4: -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.