What is the role of ribosomes in neurons?

• A. They synthesize energy for the cell
• B. They regulate ion balance
• C. They are sites of protein synthesis
• D. They store calcium

Answer: (C)

Ribosomes are the cellular machines that translate mRNA into proteins, so they are the sites where protein synthesis occurs. In neurons this matters because proteins needed at synapses—such as receptors, channels, enzymes, and cytoskeletal components—can be made locally, not just in the cell body. This local protein synthesis supports synaptic plasticity and the maintenance of dendritic spines, allowing rapid, activity-dependent changes at synapses.

Energy production comes from mitochondria, not ribosomes; ion balance is governed by channels and pumps, while calcium storage involves organelles like the endoplasmic reticulum and buffering proteins.