metabolism

American  

[muh-tab-uh-liz-uhm] / məˈtæb əˌlɪz əm /

noun

1. Biology, Physiology. the sum of the physical and chemical processes in an organism by which its material substance is produced, maintained, and destroyed, and by which energy is made available.

2. any basic process of organic functioning or operating.

   changes in the country's economic metabolism.

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metabolism British  

/ ˌmɛtəˈbɒlɪk, mɪˈtæbəˌlɪzəm /

noun

1. the sum total of the chemical processes that occur in living organisms, resulting in growth, production of energy, elimination of waste material, etc See anabolism basal metabolism catabolism

2. the sum total of the chemical processes affecting a particular substance in the body

   carbohydrate metabolism

   iodine metabolism

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metabolism Scientific  

/ mĭ-tăb′ə-lĭz′əm /

1. The chemical processes by which cells produce the substances and energy needed to sustain life. As part of metabolism, organic compounds are broken down to provide heat and energy in the process called catabolism. Simpler molecules are also used to build more complex compounds like proteins for growth and repair of tissues as part of anabolism. Many metabolic processes are brought about by the action of enzymes. The overall speed at which an organism carries out its metabolic processes is termed its metabolic rate (or, when the organism is at rest, its basal metabolic rate). Birds, for example, have a high metabolic rate, since they are warm-blooded, and their usual method of locomotion, flight, requires large amounts of energy. Accordingly, birds usually need large amounts of high-quality, energy-rich foods such as seeds or meat, which they must eat frequently.

2. See more at cellular respiration

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metabolism Cultural  

1. The total of the chemical reactions that maintain the life of a living thing.

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Discover More

In humans, metabolism is related to the intake and use of food; persons with a high metabolism can eat more without gaining weight.

Other Word Forms

• hypermetabolism noun
• metabolic adjective
• metabolically adverb

Etymology

Origin of metabolism

First recorded in 1875–80; from Greek metabol(ḗ) “change” (from meta- meta- + bolḗ “a throw”) + -ism

Compare meaning

How does metabolism compare to similar and commonly confused words? Explore the most common comparisons:

• catabolism vs. metabolism

Explanation

Your metabolism is the result of all the processes in your body working together to create the energy that keeps you going. Your metabolism is the rate at which your body's many processes function, and it can be low, high, or somewhere in the middle. When you're younger, your high metabolism makes it easy to lose weight but as you get older your metabolism slows down and you might put on a few pounds. Exercising speeds up your metabolism. This word also refers to the sudden transformation of a larva into an adult in some animals.

Example Sentences

In older mice, higher levels of the protein slowed cellular metabolism in the hippocampus.

From Science Daily • Apr. 5, 2026

This large network revealed that bacterial proteins tend to target pathways involved in immune regulation and metabolism.

From Science Daily • Mar. 27, 2026

Another study led by former graduate student Cynthia Wang-Claypool found that feathers, including those of Anna's hummingbirds, contain ethyl glucuronide, a byproduct of ethanol metabolism.

From Science Daily • Mar. 25, 2026

She wrote a letter to Kennedy in November urging the FDA to use enforcement discretion for certain peptides that she said were “critical to processes” such as metabolism, immune response and tissue repair.

From The Wall Street Journal • Mar. 22, 2026

Some of these are normal by-products of metabolism, which the liver swiftly and efficiently makes harmless by withdrawing their nitrogen.

From "Silent Spring" by Rachel Carson

Related Words

• body
• existence
• growth
• living
• man
• person
• soul
• survival
• woman