1.) the products of photosynthesis are the reactants and the other way around too
2.) cellular respiration turns glucose (or food) into energy the cell can use (ATP) almost all eukaryotes do this
3.) to convert energy from the sun (with other things) into energy (glucose)
this has to be broken down to be used but all things get their energy from the sun, producers get it directly, then primary consumers eat the producers, then secondary,and tertiary
but it is all comes from the sun originally
