Why can't eukaryotic ribosomes translate circular mrna?

mRNA translation needs a series of protein mRNA and protein-protein interactions. The structure of the mRNA of eukaryotic cells has five capes and three tail. These determinants are very im[ortant in the interaction of the eukaryotic cells. All these cells are modified at the cap level and are recognized at the initiation and binding with the cap protein eIF4e. Many of the eukaryotic cells has been modified after or post addition of three tails. The tails are the good regulator for the genetic expression.  

)

The enzyme Lactase is a transmembrane protein in intestinal epithelial cells, or enterocytes. Its function is to break lactose into its two constituent sugars: glucose and galactose. These constituent sugars can then be used in ATP manufacturing and other cellular processes.

Hope it helps you my dear:)