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.
Some power plants have an open cycle (once through) cooling water. system where water is taken from a body of water, such as a river, lake or ocean, pumped through the plant condenser and discharged. back to the source. Inland plants away from large water bodies prefer to use closed cycle.