The functions of the rough endoplasmic reticulum include which of the following?

• A. Storage of calcium ions
• B. Synthesis of lipids and steroids
• C. Detoxification of drugs and poisons
• D. Synthesis of proteins destined for secretion

Answer: (D)

Verified step by step guidance

1. Begin by understanding the structure of the rough endoplasmic reticulum (RER). It is characterized by the presence of ribosomes on its surface, which gives it a 'rough' appearance under a microscope.
2. Recognize the primary function of ribosomes, which is to synthesize proteins. The presence of ribosomes on the RER indicates its role in protein synthesis.
3. Differentiate between the functions of the rough and smooth endoplasmic reticulum. The smooth endoplasmic reticulum (SER) is involved in lipid synthesis, detoxification, and calcium ion storage, whereas the RER is primarily involved in protein synthesis.
4. Identify the specific role of the RER in the synthesis of proteins destined for secretion. Proteins synthesized by the RER are often transported to the Golgi apparatus for further processing and eventual secretion outside the cell.
5. Conclude that the rough endoplasmic reticulum is not involved in the storage of calcium ions, synthesis of lipids and steroids, or detoxification of drugs and poisons. These functions are associated with the smooth endoplasmic reticulum.