Ribosomes ⇒ small round structures ⇒ attached to the RER or lie freely in the cytoplasm

Function:

  • needed to synthesise proteins in the cell
  • those attached to RER ⇒ make proteins that are usually transported out of the cell
  • those that lie freely in the cytoplasm ⇒ make proteins that are usually used within the cytoplasm of the cell.