NEET2012BotanyCell - The Unit of LifeActual
Polysome is formed by
Options
- Aseveral ribosomes attached to a single mRNA
- Bmany ribosomes attached to a strand of endoplasmic reticulum
- Ca ribosome with several sub-units
- Dribosomes attached to each other in a linear arrangement
Correct answer
A. several ribosomes attached to a single mRNA
Step-by-step solution
In prokaryotes, ribosomes attach to the 5^ end of m RNA as soon as transcription begins. A bunch of ribosome moves along a single mRNA molecule adding 15 amino acids/second to the polypeptide chain, almost the same speed at which RNA polymerase transcribes the m RNA. The group of ribosomes together with the single mRNA molecules, they are translating is called polysome. The use of polysomes is advantageous to a cell since, the overall rate of protein synthesis is increased compared to the rate that would occur if t