Skip to main content

Ribosomes

This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.

State

A ribosome, built of large and small protein-RNA subunits, carries out protein synthesis by translating mRNA into a sequence of amino acids.

Show

Ribosomes float free in the cytoplasm or attach to the plasma membrane or ER, densest in cells that secrete heavily.

Watch for

A ribosome is not membrane-bound — it is a molecular complex, present in prokaryotes and eukaryotes alike.