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.
Health

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 Cell Metabolism?

By H.R. Childress
Updated: May 17, 2024
Views: 12,393
Share

Cell metabolism is a general term covering all of the chemical reactions that convert energy or use energy inside a cell. The cells of humans and many other multi-cellular organisms use the process of aerobic respiration to convert food into energy. Plants and some microorganisms perform the process of photosynthesis. Other organisms use anaerobic respiration or fermentation, types of cell metabolism which do not require oxygen.

Two types of chemical reactions occur in cell metabolism, catabolic reactions and anabolic reactions. Catabolic reactions produce energy for the cell to use, while anabolic reactions require energy to create molecules that are necessary for the cell to continue functioning. Cells store energy in the form of adenosine triphosphate (ATP), which is created by catabolic reactions and used by anabolic reactions.

Aerobic respiration breaks down organic sources of carbon, such as carbohydrates, proteins, and fats. First, the process of glycolysis breaks down a molecule of glucose — a sugar with six carbon atoms — into two molecules of pyruvate, two molecules of reduced nicotinamide adenine dinucleotide (NADH), and two molecules of ATP. The Kreb's cycle, also called the citric acid cycle (CAC) or the tricarboxylic acid (TCA) cycle, further breaks down the pyruvate created during glycolysis into carbon dioxide and water, creating two more molecules of ATP in the process. A mechanism called an electron transport chain transfers hydrogen atoms from NADH to oxygen. This transfer releases energy, which is used to create 34 more molecules of ATP.

Glycolysis and the Kreb's cycle take place in the same way in anaerobic respiration as they do in aerobic respiration. In the electron transport chain, however, inorganic molecules — molecules that do not contain carbon — are used as the electron acceptor in place of oxygen. The type of inorganic molecule used depends on the organism. For example, some organisms use sulphur-containing compounds, and some use nitrogen-containing compounds. Anaerobic respiration produces a total of 36 molecules of ATP, as opposed to 38 for aerobic respiration.

Fermentation is another form of anaerobic metabolism, but unlike anaerobic respiration, it does not involve an electron transport chain or the Kreb's cycle. Glycolysis breaks down organic molecules to create energy. Since glycolysis is the only reaction that takes place in fermentation, it produces only two molecules of ATP per molecule of glucose.

Plants and some microorganisms, all of which are classified as photoautotrophs, gain their energy from a form of cell metabolism called photosynthesis, rather than respiration. Photoautotrophs get energy from light and convert it to chemical energy in the form of ATP. The cells then use the ATP to convert carbon dioxide to glucose and other nutrients that the organism needs.

Share
WiseGeek 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.

Editors' Picks

Discussion Comments
Share
https://www.wisegeek.net/what-is-cell-metabolism.htm
Copy this link
WiseGeek, in your inbox

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

WiseGeek, in your inbox

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