1. Photosynthesis & Cellular Respiration
Seventh Grade Science

2. What is Photosynthesis?
Photosynthesis is an endothermic reaction wherein energy is absorbed from the sun and utilized to convert carbon dioxide (CO2 ) and water (H2O) into glucose (C6H12O6) and oxygen (O2).
6 CO H2O → 6 C6H12O O2
The energy stored in the glucose molecules is ready to be used when needed.

3. What is Cellular Respiration?
Cellular respiration is the reverse reaction of photosynthesis: the combustion of glucose to form carbon dioxide and water
Cellular respiration is an exothermic reaction.
6 C6H12O O2 → 6 CO H2O

4. Examining the Reactants and Products
Photosynthesis Reactants: 6 CO2 + 6 H2O Products: 6 C6H12O6 + 6 O2
Cellular Respiration Reactants: 6 C6H12O6 + 6 O2 Products: 6 CO2 + 6 H2O

5. Comparing & Contrasting
Photosynthesis and cellular respiration have the exact same components in the chemical equation
The reactants of photosynthesis are the same as the products of cellular respiration
The products of photosynthesis are the same as the reactants of cellular respiration

6. Quick Quiz
What is meant by “reverse reaction” when discussing photosynthesis and cellular respiration?
How do the reactants and products of photosynthesis and cellular respiration compare?