Humber Admissions Practice Test

Which cell component is responsible for the modification and transport of proteins?

1. Smooth ER

2. Golgi apparatus

3. Lysosomes

4. Nucleus

The correct answer is: Golgi apparatus

The Golgi apparatus is the cell component primarily responsible for the modification and transport of proteins. It functions as a packaging center, receiving proteins synthesized in the rough endoplasmic reticulum, processing them through various enzymatic reactions, and preparing them for their destination within or outside the cell. This process may involve glycosylation (adding sugar molecules), phosphorylation (adding phosphate groups), and the sorting of proteins into vesicles that transport them to various locations, such as the plasma membrane, lysosomes, or secretion outside the cell. Other components mentioned do have important roles but do not specialize in protein modification and transport to the same extent. The smooth endoplasmic reticulum primarily focuses on lipid synthesis and detoxification processes. Lysosomes are involved in digestion and waste processing within the cell, and the nucleus houses the cell’s genetic material but does not participate in the modification or transport of proteins. Thus, the Golgi apparatus is essential for ensuring proteins are correctly modified and directed to their appropriate locations, making it the correct response in this context.