What is the function of ribosomes?

• A. To generate ATP.
• B. To synthesize proteins by translating mRNA.
• C. To degrade waste in lysosomes.
• D. To store calcium.

Answer: (B)

Ribosomes are the molecular machines that build proteins by translating messenger RNA into polypeptide chains. They read the genetic code carried by mRNA, match each codon with the appropriate transfer RNA carrying an amino acid, and then link those amino acids together to form a growing protein. This process can happen freely in the cytoplasm or on the rough endoplasmic reticulum, depending on where the protein will function. The ribosome’s role is fundamentally about making proteins, not about energy production, waste breakdown, or calcium storage. ATP is mainly produced by mitochondria, lysosomes handle waste degradation, and calcium storage is associated with the ER and other organelles. So the function described here—synthesizing proteins by translating mRNA—best fits what ribosomes do.