which group of organelles is directly responsible for the production of new molecules within a cell?

The group of organelles directly responsible for the production of new molecules within a cell is mainly the endoplasmic reticulum (ER) and the ribosomes associated with it. The rough endoplasmic reticulum (rough ER), studded with ribosomes, is involved in the synthesis of proteins, which are key new molecules in the cell. The smooth ER produces vital lipids. Additionally, the Golgi apparatus modifies, sorts, and packages proteins produced by the rough ER for use inside or outside the cell, further contributing to molecular production and processing within the cell.