What is the structure of ribosomes?

Ribosomes are made from complexes of RNA and protein. About 62% of ribosomes are composed of RNA, while the rest are proteins. Each ribosome is composed of two subunits of unequal sizes, called the smaller and larger subunit. Because of the different sizes of the subunits, ribosomes have a slightly longer axis as compared to the diameter. The smaller and larger subunits fit together and work as one unit during protein synthesis. The mRNA binds and decodes in the smaller subunit, while the amino acids are included in the larger subunit. Ribosomes have a temporary existence. The two subunits separate after the synthesis of polypeptide and may either be reused or broken up.