1. Ribosomes:
- These are the protein factories of the cell. They are complex molecular machines made of ribosomal RNA (rRNA) and proteins.
- Ribosomes move along messenger RNA (mRNA) molecules, reading the genetic code and assembling amino acids into polypeptide chains.
2. Endoplasmic Reticulum (ER):
- The ER is a network of interconnected membranes that plays a crucial role in protein synthesis and other cellular processes.
- Ribosomes attached to the ER (called "rough ER") synthesize proteins that are destined for export out of the cell or for use in specific organelles.
- The ER also assists in protein folding and modification.
Summary:
* Initiation and elongation of the polypeptide chain: Ribosomes
* Protein folding, modification, and transport: Endoplasmic reticulum (ER)
It's important to note that some proteins are synthesized solely by ribosomes in the cytoplasm, while others are synthesized by ribosomes on the ER and then further processed and transported.
