USA Biology Olympiad (USABO) Practice Exam

Which structure is critical in the process of translation in prokaryotic cells?

1. Ribosome

2. Endoplasmic Reticulum

3. Nucleus

4. Golgi Apparatus

The correct answer is: Ribosome

The ribosome is the critical structure in the process of translation in prokaryotic cells. Ribosomes are the cellular machinery responsible for synthesizing proteins by translating messenger RNA (mRNA) sequences into amino acid chains. In prokaryotes, translation occurs in the cytoplasm where ribosomes bind to the mRNA and facilitate the assembly of amino acids into polypeptides, responding directly to the codons present in the mRNA. The ribosome consists of two subunits, each made of ribosomal RNA (rRNA) and proteins. During translation, the small subunit binds to the mRNA, while the large subunit joins to form a complete ribosome that can catalyze the formation of peptide bonds between amino acids, ultimately producing a functioning protein. This process is vital for prokaryotic cells as they rely on protein synthesis for growth, metabolism, and response to environmental changes. In contrast, the endoplasmic reticulum, nucleus, and Golgi apparatus are structures primarily associated with eukaryotic cells. The endoplasmic reticulum plays a role in the synthesis of proteins and lipids but does not participate directly in translation in prokaryotes. The nucleus houses genetic material and is involved in transcription rather