Question

The immediate source of energy that powers a cell’s activities is

adenosine triphosphate
food
adenosine diphosphate
sugar

Answer 1

I'll eliminate 2 choices:

1. food (this is not a word that's used to describe energy sources at the cellular level)
2. sugar (a sugar is a *possible* source of energy, but it's not the only source, plus sugar can be broken down into an even more immediate energy source)

so we're between adenosine triphosphate (ATP) and adenosine diphosphate (ADP). try to look up these two terms and see which one is better suited as an energy source (has something to do with the # of phosphate groups)