In this situation, translation begins at the 5' end of the mRNA while the 3' end is still attached to DNA. In all types of cells, the ribosome is composed of two subunits: the large (50S) subunit and the small (30S) subunit (S, for svedberg unit, is a measure of sedimentation velocity and, therefore, mass).
The most common types of nuclear power plants use water for cooling in two ways: 1  To convey heat from the reactor core to the steam turbines. 2  To remove and dump surplus heat from this steam circuit.
The water cooling towers chills the fluid by the use of water instead of air cooling and is recognized as most efficient. In this case the condenser does not cool the hot refrigerant with ambient air, but uses a cooling tower.