ATP is formed of an adenine, ribose and a row of three phosphate radicals attached to ribose. The last two phosphate radicals are attached by bonds of high transfer potential. They are also called energy rich bonds. The bond between second and third phosphate radicals possesses and energy equivalent to 8.15 kcal/mole. This bond is also known as terminal phosphate linkage. This bond can be very easily synthesised and broken up.