The word equations for photosynthesis and respiration are similar in that they both involve the same reactants and products, but in reverse order:

Photosynthesis:

* Reactants: Carbon dioxide + water + light energy

* Products: Glucose + oxygen

Cellular Respiration:

* Reactants: Glucose + oxygen

* Products: Carbon dioxide + water + energy (ATP)

Similarities:

* Both involve glucose: Photosynthesis produces glucose, while respiration uses glucose as fuel.

* Both involve oxygen and carbon dioxide: Photosynthesis uses carbon dioxide and releases oxygen, while respiration uses oxygen and releases carbon dioxide.

* Both involve energy transformations: Photosynthesis captures light energy to create chemical energy in glucose, while respiration releases energy stored in glucose.

Key difference: Photosynthesis is an anabolic process that builds complex molecules (glucose) from simpler ones, while respiration is a catabolic process that breaks down complex molecules (glucose) into simpler ones.