Which structure is part of the endomembrane system involved in protein secretion?

• A. Ribosome
• B. Golgi apparatus
• C. Mitochondria
• D. Chloroplast

Answer: (B)

Verified step by step guidance

1. Understand the endomembrane system: The endomembrane system is a group of membranes and organelles in eukaryotic cells that work together to modify, package, and transport lipids and proteins. It includes the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, and vesicles.
2. Identify the role of the Golgi apparatus: The Golgi apparatus is a key component of the endomembrane system. It is involved in the modification, sorting, and packaging of proteins for secretion. Proteins synthesized in the rough endoplasmic reticulum are transported to the Golgi apparatus.
3. Distinguish between the structures listed: Ribosomes are involved in protein synthesis but are not part of the endomembrane system. Mitochondria and chloroplasts are involved in energy production and photosynthesis, respectively, and are not part of the endomembrane system.
4. Focus on protein secretion: The Golgi apparatus receives proteins from the endoplasmic reticulum, processes them, and then packages them into vesicles for transport to the cell membrane, where they are secreted outside the cell.
5. Conclude with the correct structure: Based on the roles and functions of the listed structures, the Golgi apparatus is the correct answer as it is part of the endomembrane system and directly involved in protein secretion.