Final answer:
The ER, consisting of rough (RER) and smooth (SER) regions, functions in protein synthesis, lipid metabolism, calcium ion regulation, and detoxification. The RER, with ribosomes, synthesizes membrane and secretory proteins, while the SER is involved in lipid and carbohydrate metabolism.
Step-by-step explanation:
The endoplasmic reticulum (ER) is an essential organelle in eukaryotic cells with functions that include protein synthesis, lipid metabolism, and detoxification. The ER is divided into two types: the rough endoplasmic reticulum (RER) and the smooth endoplasmic reticulum (SER). The RER is covered with ribosomes and is primarily involved in the synthesis of proteins that will be secreted from the cell, become part of the cell's membrane, or shipped to an organelle.
Ribosomes on the surface of the RER read mRNA and create polypeptide chains, which are then folded and modified in the ER. On the other hand, the SER lacks ribosomes and is involved in synthesizing lipids such as phospholipids and steroids, regulating calcium ion levels, metabolizing carbohydrates, and detoxifying drugs and poisons.
Both types of ER contribute to the transport of materials within the cell through the creation and dispersal of vesicles.