Cellular Respiration

In order for a cell to carry out its functions, it requires energy in the form of ATP. Cellular respiration is the way cells make this ATP, using food as its fuel. is the most common starting point for cellular respiration (although other sugars, fats and proteins can also be used).

The overall equation for cellular respiration is


Glucose + Oxygen --> Carbon Dioxide + Water + Energy

C6H12O6 + O2 --> CO2 + H2O + ATP


The energy released from glucose is step-wise, releasing small amounts of energy each time that can be used. If we released all the energy contained in glucose it would be too much for the cells to handle!

Cellular respiration involves 3 different stages:
1 Glycolysis
2 The Kreb's cycle (or citric acid cycle)
3 The electron transport chain