Here's why:
* RER Structure: The RER is a network of interconnected membranes studded with ribosomes.
* Protein Synthesis: Ribosomes translate mRNA into proteins.
* Targeting Signal: Membrane receptors have a signal sequence that directs them to the RER. This signal sequence is recognized by a signal recognition particle (SRP), which escorts the ribosome-mRNA complex to the RER.
* Translocation: Once at the RER, the protein is threaded through a protein channel called a translocon and inserted into the RER membrane.
Therefore, the synthesis of membrane receptors on ribosomes attached to the RER is essential for their proper localization and function within the cell membrane.
