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.
This type of cooling tower is very similar to that of the spray type. Instead of a spray header, a water box is used. The water box has small holes at the bottom. It also contains decking inside the tower. The hot water from the condenser enters into the water box and splashes via holes in the water box on the decking.