Protein Trafficking Practice Test 2025 – Comprehensive Exam Prep

The process that delivers proteins from the inside of the cell to the outside is exocytosis. This mechanism involves the transport of materials in vesicles that fuse with the cell membrane, releasing their contents into the extracellular environment.

Exocytosis is fundamental for various cellular functions, including the secretion of hormones, neurotransmitters, and digestive enzymes. During this process, proteins synthesized in the endoplasmic reticulum are packaged into vesicles and transported to the Golgi apparatus for modification and sorting. Once processed, these vesicles move towards the plasma membrane, where they merge with it, allowing the proteins to be expelled from the cell.

The other processes mentioned, such as absorption and endocytosis, pertain to the uptake or internalization of materials into the cell, rather than the export of proteins. Secretion, while sometimes used colloquially to describe the release of substances, is more accurately described through exocytosis when detailing how proteins specifically are transported to the outside of the cell.