Which organelle is responsible for protein production?

• A. Mitochondria
• B. Cytoplasm
• C. Ribosomes
• D. Nucleus

Answer: (C)

Ribosomes are the molecular machines that carry out protein production by translating messenger RNA into polypeptide chains. They read the genetic code and link amino acids in the order specified, building proteins. They can float freely in the cytoplasm to make cytosolic proteins or attach to the endoplasmic reticulum to produce proteins destined for secretion or membranes. While mitochondria perform energy-related tasks and house their own limited translation system for a subset of proteins, the bulk of cellular protein synthesis happens at ribosomes. The nucleus houses DNA and handles transcription, not the assembly of proteins, and the cytoplasm is the site where translation occurs but is not itself the protein-assembly machinery.