Once DNA signals to make proteins, which organelles are responsible for receiving this message and transporting the proteins?

The endoplasmic reticulum and Golgi apparatus play crucial roles in the process of protein synthesis and transport within the cell. Once DNA is transcribed into messenger RNA (mRNA) in the nucleus, this mRNA travels to the ribosomes, where it is translated into proteins. After the initial stage of protein synthesis at the ribosomes, the proteins are then typically folded and modified in the rough endoplasmic reticulum (ER), an organelle studded with ribosomes.

Once the proteins are adequately processed in the rough ER, they are packaged into vesicles and sent to the Golgi apparatus. The Golgi apparatus further modifies, sorts, and packages the proteins for their eventual destinations, whether that's outside the cell, to various organelles, or for use within the cytoplasm. This pathway is key for ensuring that proteins are correctly processed and reach their required locations to perform their functions.

Other choices involve organelles that either do not directly participate in the transportation of proteins or perform different primary functions. The nucleus, while important for the initial stages of protein synthesis, does not transport proteins. Vesicles can help in transport but are not primary organelles responsible for protein processing or packaging. Lysosomes are involved in digestion and waste processing,