n.
1.short-chain RNA molecules present in the cell (in at least 20 varieties, each variety capable of combining with a specific amino acid) that attach the correct amino acid to the protein chain that is being synthesized at the ribosome of the cell (according to directions coded in the mRNA)
Idiom of the Day
make (something) up to (someone)
to repay someone for something, to make amends to someone
I was late for work so I had to make it up to my boss by working late.