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.
Thermoelectric Coolers and Cooling Modules. Acting as a solid-state heat pump, thermoelectric modules produce a heating, cooling or stabilization effect by running electrical energy through the device and transferring heat from one side of the device to another against the temperature gradient.