Difference Between Fermentation and Respiration

The key difference between fermentation and respiration is that the fermentation occurs in the absence of oxygen while the respiration needs oxygen.

Organisms require energy to perform cellular activities. Hence, they generate energy molecules in the form of ATP. They use different substrates and break down into different forms, and the releasing energy converts into energy molecules that can be used by the cells. Glucose is the primary substrate of many organisms. Fermentation and respiration are two cellular processes which generate energy by breaking down glucose via several steps. However, respiration is more efficient and produces more ATP molecules than the fermentation.

CONTENTS

1. Overview and Key Difference
2. What is Fermentation
3. What is Respiration
4. Similarities Between Fermentation and Respiration
5. Side by Side Comparison – Fermentation vs Respiration in Tabular Form
6. Summary

What is Fermentation?

Organisms carry out fermentation to synthesize ATP when the absence of oxygen. In brief, fermentation is the process of energy production that occurs at anaerobic conditions. As a result of fermentation, sugars metabolize primarily to effervescent fatty acids. Since it does not require any oxygen, it utilizes glucose as a reactant and then produces ATP and other products.

During the primary fermentation, sugars of maltose and glucose convert into ethanol, lactic acid and carbon dioxide. It produces less energy (2 ATP) since it produces energy directly from glucose. Furthermore, in fermentation, partial breakdown of the substrate occurs. Fermentation can take place via two ways namely ethanol fermentation and lactic acid fermentation. Final electron acceptor of the fermentation is an organic molecule instead of oxygen. Fermentation usually can be seen in microbes such as yeast, bacteria, etc.

What is Respiration?

Respiration is a cellular process of energy production in aerobic organisms. It uses glucose as the substrate and from one glucose molecules, it synthesizes a total of 36 ATP molecules. Respiration requires oxygen to produce energy. It occurs via three major phases; glycolysis, Krebs cycle and electron transport chain.

Glycolysis takes place in the cytoplasm of the cell while Krebs cycle and electron transport chain occur in mitochondria. At the end of the whole process, it yields a higher number of ATP or energy than any other energy production processes. The produced energy is used for other physiological functions such as muscle contraction and electrical impulses.

What are the Similarities Between Fermentation and Respiration?

• They are cellular processes.
• Both processes are catabolic processes.
• Fermentation and Respiration involve in the breakdown of glucose into energy molecules ATP.

What is the Difference Between Fermentation and Respiration?

Fermentation and respiration are two processes that create energy from a glucose molecule. Fermentation creates the energy without needing oxygen, which hastens the growth of microorganisms. On the other hand, respiration requires oxygen in order to create the energy from glucose, this, in turn, makes the glucose go through glycolysis to produce pyruvate. Therefore, the key difference between fermentation and respiration is regarding the oxygen requirement mentioned above. Furthermore, this pyruvate then undergoes cellular changes where it passes through different processes and then produces ATP as an end result.

The below infographic presents more details on the difference between fermentation and respiration in tabular form.

Summary – Fermentation vs Respiration

Fermentation happens during anaerobic condition. As a result, glucose metabolizes primarily to effervescent fatty acids. Respiration is the process that produces energy from glucose when the oxygen is present. Then the fermentation, respiration produces more ATP from one glucose molecule. Furthermore, a complete breakdown of the substrate occurs in respiration while a partial break down occurs in fermentation. This is the difference between fermentation and respiration.

Reference:

1.“Fermentation and Anaerobic Respiration.” Khan Academy, Khan Academy. Available here
2.“Cellular Respiration.” Wikipedia, Wikimedia Foundation, 21 June 2018. Available here

Image Courtesy:

1.”Ethanol fermentation-1″By Davidcarmack – Own work, (CC BY-SA 3.0) via Commons Wikimedia
2.”CellRespiration”By RegisFrey – Own work, (CC BY-SA 3.0) via Commons Wikimedia