NANP Board Practice Exam

What is the primary role of ribosomes in a cell?

1. Energy production

2. Lipid synthesis

3. Protein synthesis

4. Waste elimination

The correct answer is: Protein synthesis

The primary role of ribosomes in a cell is indeed protein synthesis. Ribosomes are the cellular machinery responsible for translating messenger RNA (mRNA) into amino acid sequences, effectively building proteins based on the genetic instructions encoded within the mRNA. This is crucial because proteins are involved in virtually all cellular functions, serving as enzymes, structural components, signaling molecules, and more. In contrast, energy production is primarily carried out by mitochondria, which convert nutrients into ATP, the energy currency of the cell. Lipid synthesis occurs in the smooth endoplasmic reticulum and involves the creation of fatty acids and other lipid molecules, while waste elimination is typically handled by lysosomes and other cellular mechanisms designed to degrade and expel waste materials from the cell. Thus, the distinct and essential function of ribosomes as the site of protein synthesis highlights their fundamental role in cellular biology.