We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Biology

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What Is Anaerobic Respiration?

By Greg Caramenico
Updated: May 21, 2024
Views: 19,619
Share

In biology, anaerobic respiration is the metabolic process through which cells produce chemical energy without using oxygen. It is a type of cellular respiration, an essential part of metabolism and the source of all the growth, reproduction, and repair that happens in cells. Glycolysis, which converts sugar into energy molecules, is the main type of anaerobic pathway found in most organisms. Anaerobic metabolism facilitates important chemical exchanges between organisms and the environment, like the nitrogen cycle.

All living organisms use energy to power their growth and reproduction. Cellular respiration is a type of cellular metabolism that extracts biochemical energy from various nutritive chemicals and converts it into ATP, the universal energy transfer molecule. Anaerobic respiration is the kind of cellular respiration occurring in cells that do not use molecules of oxygen in their metabolism. The primary chemical pathway of anaerobic respiration — apart from extreme metal-ingesting bacteria — is glycolysis, which divides a molecule of the simple sugar glucose into two molecules of pyruvic acid, producing two molecules of ATP in the process.

Aerobic respiration — using oxygen — is more common than anaerobic in most higher organisms, which efficiently rely on oxygen for respiration. It produces a lot more ATP — 38 molecules — than does glycolysis, which yields only two. In the earliest periods of the evolution of life on earth, however, there was insufficient oxygen in the atmosphere for cells to metabolize, so they relied on various other molecules to produce energy anaerobically. Primitive organisms, including the oldest surviving bacteria and creatures living in hot springs and on the ocean floor, still rely on this; many of these will die if exposed to oxygen.

Humans and other animals use both aerobic and anaerobic respiration. The latter is important during short bursts of muscular activity, which powers movement using glycolysis and produces lactic acid. If this acid builds up, muscular pain and cramping result. Some yeasts incorporate a special kind of anaerobic respiration — fermentation — into their metabolism. Fermentation digests sugars and yields ethyl alcohol and some gases as a byproduct; this is the reason why bread rises, as biochemical processes in yeast change the chemical reactions in the dough.

The elemental exchanges of nitrogen, sulfur, and carbon on the earth's surface and in the atmosphere are moderated by anaerobic respiration. For instance, proteins and other biologically essential compounds contain a great deal of nitrogen, which is released back into the atmosphere by bacterial anaerobic metabolism. When some bacteria metabolize fuels without oxygen, they also release methane gas. While this function is useful in microbiology and the petroleum industry, the excess production of methane is a problem because it is as a much of a greenhouse gas as is carbon dioxide, linked to climate change.

Share
All The Science is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
Share
https://www.allthescience.org/what-is-anaerobic-respiration.htm
Copy this link
All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.

All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.