* RER: The site of protein synthesis and initial modification:
* Extracellular enzymes are proteins. The RER is responsible for synthesizing these proteins, and its ribosomes attach to the mRNA molecules to begin the process.
* The RER also initiates modifications like folding and glycosylation (adding sugar chains), which are crucial for proper protein structure and function.
* Golgi apparatus: The processing and packaging center:
* After leaving the RER, proteins are transported to the Golgi apparatus. Here, further modifications like glycosylation and sorting occur.
* The Golgi also packages proteins into secretory vesicles, which are then transported to the cell surface for release outside the cell.
Without the RER and Golgi, the following would occur:
* No protein synthesis: The absence of ribosomes on the RER would mean no protein synthesis can occur.
* No proper folding and modification: The RER is responsible for initial protein folding and glycosylation. Without it, proteins would likely be misfolded and dysfunctional.
* No packaging and secretion: The Golgi is the master of protein packaging. Without its function, the proteins would not be sorted, packaged, or transported to the cell surface.
Outcome: The absence of both organelles would result in a complete failure to produce and secrete extracellular enzymes. This would have profound consequences for the organism, as extracellular enzymes are vital for a multitude of processes, including digestion, tissue remodeling, and defense against pathogens.
