Final answer:
The combination of an mRNA and bound ribosomes in translation is called a polyribosome, or polysome, which enhances protein synthesis efficiency.
Step-by-step explanation:
The combination of messenger RNA (mRNA) and many bound ribosomes in the process of translation is called a polyribosome, or polysome. Polysomes refer to the structure including an mRNA molecule that is being translated by multiple ribosomes concurrently.
This arrangement significantly increases the efficiency of protein synthesis, as multiple ribosomes can produce several copies of a protein from a single mRNA transcript at the same time.
This efficient mechanism allows for a high rate of protein synthesis, with each ribosome moving along the mRNA, translating it from the 5' to the 3' direction and synthesizing the protein from the N terminus to the C terminus.