<span>Deoxyribose is the same as ribose, except that the former has one more OH. DNAand RNA is the sugar, with 2-deoxyribose being replaced by the alternative pentosesugar ribose in RNA. The four bases found in DNA are adenine (abbreviated A), cytosine (C), guanine (G) and thymine (T).</span>
The term in question is referred to as osmoregulation.
Since water and its soluted metabolites are key to the survival and normal function of the cell, there are many membrane proteins that regulate the exchange of water, ions and other osmolites between the cell and its surroundings.
Because it's where they live.
