The most common example of transport in cells is performed by adenosine triphosphate, or ATP, which both transports energy inside the cell and acts as a unit of energy for certain metabolic processes.
The ATP molecule transports three oxygen-phosphate groups, which are used in chemical reactions around the cell. The ATP is changed to ADP (diphosphate, for the removal of the third phospate), which is then recycled by mitochondria so it can transport more energy. Because the need for energy inside the cell is so immense, cells carry up to one billion ATP at any given time, and each ATP molecule has its extra oxygen-phosphate removed "3 times each minute" (trueorigin.org).
◘DIFFUSION :- IT IS THE SPONTANEOUS MOVEMENT OF GASES FROM THE HIGH PRESSURE AREA TO LOW PRESSURE AREA
E.G. :- MOVEMENT OF OXYGEN AND CARBONDIOXIDE INSIDE AND OUSIDE THE CELL
◘ OSMOSIS :- IT IS THE PAGGAGE OF WATER FROM A AREA OF HIGH WATER CONCENTRATION TO AREA O LOW WATER CONCENTRATION
E.G :- MOVEMENT OF SALTS, LIQUIDS ETC INSIDE THE CELL THROUGH PERMEABLE MEMBRANE