Summary
The process of releasing energy from glucose to make ATP, using oxygen in the aerobic form.
In depth
Stages: glycolysis (cytoplasm), link reaction, Krebs cycle (mitochondrial matrix) and oxidative phosphorylation (inner membrane). Overall: C6H12O6 + 6O2 gives 6CO2 + 6H2O + about 30 ATP. About 40 percent of the energy is captured; the rest is heat.
Glucose oxidation is stepwise so energy is released in manageable packages. Oxygen is needed only at the final stage. Heat is produced from the inefficiency.
Example: the respiration equation summarises about thirty reactions.
Cellular respiration oxidises organic molecules, chiefly glucose, to release energy for ATP synthesis. The overall equation is C6H12O6 + 6O2 gives 6CO2 + 6H2O + energy.
It occurs in four stages: glycolysis in the cytoplasm, the link reaction and Krebs cycle in the mitochondrial matrix, and oxidative phosphorylation on the inner membrane. Roughly 40 percent of the energy of glucose is captured in ATP, the rest is lost as heat which helps warm endotherms.
Example: breathing out CO2 is evidence of respiration happening in every cell.
Common mistake: respiration is not breathing; breathing is gas exchange, respiration is the chemical process in cells.
Frequently asked questions
What is Cellular Respiration?
The process of releasing energy from glucose to make ATP, using oxygen in the aerobic form.
Which area of biology covers Cellular Respiration, and how advanced is it?
Cellular Respiration is one of the 53 topics in Metabolism & Bioenergetics. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Oxidative Phosphorylation, Respiratory Equation, Anabolism and Catabolism.
Can you give an example of Cellular Respiration?
Warm-bloodedness depends on heat from respiration.
What should I learn before Cellular Respiration?
Cellular Respiration is a Beginner topic, so no earlier topic is required. Other Beginner topics in Metabolism & Bioenergetics that pair well with it include Metabolism, Anabolism and Catabolism, ATP.
What topics are related to Cellular Respiration?
The closest topics to Cellular Respiration are Oxidative Phosphorylation, Respiratory Equation, Anabolism and Catabolism, Photosynthesis vs Respiration. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Cellular Respiration?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Cellular Respiration. To practise the whole of Metabolism & Bioenergetics, use the Metabolism & Bioenergetics quiz.
How is Cellular Respiration different from Oxidative Phosphorylation?
Cellular Respiration: The process of releasing energy from glucose to make ATP, using oxygen in the aerobic form. Oxidative Phosphorylation: ATP synthesis driven by electron transport and the proton gradient across the inner membrane. Read both side by side and note what each one explains.
What is a common mistake about Cellular Respiration?
Respiration is not breathing; breathing is gas exchange, respiration is the chemical process in cells.
How should I study Cellular Respiration step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Oxidative Phosphorylation and explain the difference aloud. Finally, take the Metabolism & Bioenergetics quiz and come back to this page for any question you miss.