Algonquin College Health Program Assessment (AC-HPAT) Practice Exam

What is the primary function of ribosomes in a cell?

1. Energy production

2. Protein synthesis

3. DNA replication

4. Cell signaling

The correct answer is: Protein synthesis

The primary function of ribosomes in a cell is protein synthesis. Ribosomes are complex molecular machines found within all living cells that facilitate the translation of messenger RNA (mRNA) into polypeptide chains, which then fold into functional proteins. This process is crucial because proteins play essential roles in nearly all cellular functions, including acting as enzymes, structural components, and signaling molecules. Ribosomes can be found freely floating in the cytoplasm or attached to the endoplasmic reticulum, and they read the sequences of nucleotides in mRNA and assemble the corresponding amino acids in the correct order based on that sequence. Other options do not describe the primary function of ribosomes. While energy production occurs in mitochondria and other specific organelles, DNA replication is primarily carried out by DNA polymerase in the nucleus, and cell signaling involves various receptors and signal transduction pathways that do not directly involve ribosomes in their main functions. Thus, understanding ribosomes' role in the synthesis of proteins is fundamental for appreciating how cells build and maintain their structures and functions.