A Level Biology Practice Exam

What is the primary function of the Golgi apparatus in eukaryotic cells?

1. Storage of genetic information

2. Modification and packaging of proteins

3. Production of energy through respiration

4. Synthesis of carbohydrates

The correct answer is: Modification and packaging of proteins

The primary function of the Golgi apparatus in eukaryotic cells is indeed the modification and packaging of proteins. This organelle plays a crucial role in the secretory pathway, where it receives proteins synthesized in the rough endoplasmic reticulum. Once the proteins reach the Golgi apparatus, they undergo various modifications, such as glycosylation, phosphorylation, and sulfation, which are essential for their final functional form and activity. After these modifications, the Golgi apparatus packages the proteins into vesicles that can either be directed to their final destinations within the cell, such as lysosomes, or secreted outside the cell via exocytosis. This ability to modify and sort proteins is vital for proper cellular function, as it ensures that proteins are properly processed and delivered where they are needed. In contrast, the other choices represent functions carried out by different cellular structures: the storage of genetic information is primarily the role of the nucleus; the production of energy through respiration occurs mainly in mitochondria; and while the Golgi apparatus can be involved in the synthesis of some carbohydrates, this is not its primary function, as that role is more associated with other organelles like the chloroplasts in plants and the endoplasmic reticulum for certain polys