Which set of terms best identifies the letters in the diagram below?

By which process is the stored energy of organic molecules transferred to a form of energy that is usable by cells? 1) digestion 3) photosynthesis 2) aerobism 4) respiration

Cells need ATP energy (“small bites”) ATP made from food energy (respiration) Food energy is from sun (photosynthesis)

The diagram represents part of a cellular process . Energy is released and made available for metabolic activities at 1) step 1, only 3) both step 1 and step 2 2) step 2, only 4) neither step 1 nor step 2

CO2 + H2O + ATP Enzymes C6H12O6 + O2 Photosynthesis CO2 + H2O + Sunlight Enzymes C6H12O6 + O2 Cellular respiration CO2 + H2O + ATP Enzymes C6H12O6 + O2