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.
On a much larger scale, solar-thermal power plants employ various techniques to concentrate the sun's energy as a heat source. The heat is then used to boil water to drive a steam turbine that generates electricity in much the same fashion as coal and nuclear power plants, supplying electricity for thousands of people.