We all know that we need energy to stay alive. We get this energy from the food we eat. During digestion, food is broken down into simpler substances.
For example, rice, potatoes and bread contain carbohydrates. These carbohydrates are broken down to form glucose.
This glucose combines with oxygen in the cells of our body and provides energy. The special name of this reaction is respiration.
C6H12O6 (aq) + 6O2 (aq) → 6CO2 (aq) + 6H2O (l) + energy