Frederick Miescher first identified DNA.
DNA provides the instructions for protein production.
hope this helps
ATP is adenosine triphosphate, it is like a fully charged battery in a cell, ADP is basically ATP that has been drained of its energy from a chemical reaction. It is like a dead battery that can be recharged later ;)
Other molecules such as proteins, starch and sugar are simply too large to diffuse across the membrane. Sometimes, some of these large molecules are transported across the cell membranes by carrier proteins; this does not require energy and as a result is a form of passive transpor