What is the main function of ribosomes in a cell?

• A. To replicate DNA
• B. To synthesize proteins
• C. To degrade waste materials
• D. To generate ATP

Answer: (B)

Ribosomes are essential cellular structures primarily responsible for synthesizing proteins. They are comprised of ribosomal RNA (rRNA) and proteins, often found free-floating in the cytoplasm or attached to the endoplasmic reticulum, forming rough ER. The process of protein synthesis involves translating messenger RNA (mRNA) sequences into polypeptide chains, ultimately folding into functional proteins.

During translation, ribosomes facilitate the linkage of amino acids in the order specified by the mRNA, incorporating tRNA molecules that transport the correct amino acids to the ribosome. This process is crucial for the production of enzymes, structural components, and signaling molecules necessary for various cellular functions.

The other options pertain to different cellular functions. DNA replication is carried out by DNA polymerases, degradation of waste materials is typically managed by lysosomes, and ATP generation primarily occurs in mitochondria through cellular respiration. Thus, the primary and crucial role of ribosomes centers on protein synthesis.