what do all cellular activities in living organisms use as a source of energy?\natp\nlactic acid\npyruvic…

Brief Explanations:

ATP (adenosine - triphosphate) is the energy - currency of the cell. It provides the energy required for all cellular activities in living organisms. Lactic acid, pyruvic acid, and carbon dioxide are by - products or involved in other metabolic processes but not the main energy source for cellular activities.

Answer:

ATP