Final answer:
ATP stands for adenosine triphosphate, which is the universal energy carrier molecule in living cells, used to transfer energy for various metabolic processes.
Step-by-step explanation:
The 3-letter abbreviation for the energy carrier molecule that powers all life processes is ATP, which stands for adenosine triphosphate. ATP is known as the 'energy currency' of the cell, and it plays a crucial role in transferring energy from sources such as glucose to the various energy-requiring processes within cells. A remarkable aspect of ATP is its universal presence across different forms of life, from the simplest microorganisms to the most complex plants and animals, underscoring the unity of life.
Cells use ATP to power metabolic pathways, particularly those involved in the synthesis of large molecules like proteins, lipids, nucleic acids, and complex carbohydrates from smaller ones. The energy stored in the phosphate bonds of ATP molecules is released to fuel these biological processes. Moreover, cells are capable of regenerating ATP from its lower-energy form, adenosine diphosphate (ADP), allowing for the continuous use and recycling of ATP.