Final answer:
Proteins and lipids synthesized in the ER are transported to the Golgi apparatus via transport vesicles for processing and sorting. Modifications, such as the addition of sugar molecules, happen in the Golgi before they reach their final destinations.
Step-by-step explanation:
The materials that move from the endoplasmic reticulum (ER) to the Golgi apparatus within transport vesicles are primarily proteins and lipids. These substances are synthesized in the ER, and then transported to the Golgi apparatus for further modification, sorting, and packaging.
The most common modification during their transit through the Golgi involves the addition of short chains of sugar molecules, which is critical for determining their final destinations. Motor proteins like dynein and kinesin facilitate the movement of these vesicles along microtubule tracks in the cytoplasm. Eventually, these vesicles are either sent to be fused with the plasma membrane or directed to other organelles within the cell.