Which organelle carries substances, such as proteins, to various parts of the cell?

• A. Endoplasmic Reticulum
• B. Nucleolus
• C. Chloroplast
• D. Vacuole

Answer: (A)

Proteins and other newly made substances are moved around the cell through an internal transport system, and the endoplasmic reticulum serves as a central part of that system. The rough ER, studded with ribosomes, builds proteins and packages them into vesicles that bud off and travel to other destinations, such as the Golgi apparatus for further processing or directly to the cell membrane or lysosomes. This role of creating and shuttling proteins to different parts of the cell makes it the best description of carrying substances like proteins. The nucleolus mainly makes ribosomal components, chloroplasts perform photosynthesis, and vacuoles store materials, so they aren’t described as transporting proteins to various cellular locations.