Question

The ion required to keep the two ribosomal units together during protein synthesis is
A. $K^+$
B. $Mg^{++}$
C. $CI^-$
D. All of the above

Answer 1

Hint: Ribosomes are micro-organelles that are found inside the cell and assist in protein synthesis. Protein is required in many processes as in repair damage and chemical processes. These are found floating or attached to endoplasmic reticulum.

Complete answer:
Ribosome is a ribonucleoprotein that consists of a rRNA and a r-protein. It acts as a small migrating factory. They have two major functions decoding the message and formation of peptide bonds.
The structure consists of two sections that are called as subunits usually one is smaller than the other. The smaller subunit is the place where mRNA binds and it decodes it and the larger subunit is the place of amino acid.
These two subunits are attached together in presence of $Mg^+$ and in presence of K+ leads to disassociation of the two subunits. $Mg^{2+}$ is essential for two vital processes as in for stabilization of the secondary structure of rRNA and binding of the ribosomal proteins to the rRNA.
So, the ion required to keep the two ribosomal units together during protein synthesis is $Mg^+$.

The correct answer is option B.

Note:
There are two types of ribosome, eukaryotic ribosome that are 80S and has two subunits of 60s and 40s and prokaryotic ribosomes that are of 70s size with two subunits of 50s and 30s.