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 from 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.

What is Metabolic Activity?

By Rachel Burkot
Updated Mar 03, 2024
Our promise to you
The Health Board is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

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.

Editorial Standards

At The Health Board, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Metabolic activity refers to the set of chemical reactions that maintain life in any organism. Metabolic activity involves the transformation of energy and matter in the body, two elements that must always be present for life to be sustained. Two types of metabolic processes are anabolism and catabolism. Anabolism is constructive metabolism, during which small molecules are formed into larger ones, requiring an input of energy. Catabolism is the opposite process; it necessitates an output of energy, and large molecules are broken into smaller ones.

Human beings are heterotrophs, which means that humans are dependent on organic molecules that have been ingested to meet energy needs. Organic molecules are the building blocks that meet anabolic needs as well. Metabolic activity begins with ingestion, when food is taken into the body. Metabolic enzymes come into play during digestion, when food is broken down in the body through a process called hydrolysis. During hydrolysis, starches become sugars, proteins become amino acids, fats become fatty acids and glycerol, and nucleic acids become nucleotides.

After digestion, metabolic activity continues with absorption into the body and transportation to the cells, where it enters them. Once the food parts are in the cells, the molecules continue to break down until they contain between two and four carbon atoms. The molecules might continue up the metabolic pathways and become building blocks for sugar and amino acids. The new parts of the cell, which include polysaccharides, proteins, fats and nucleic acids, are then assembled.

Another option is that the molecules may be further broken down into inorganic molecules like water, carbon dioxide and ammonia. Large amounts of energy are released during this phase of metabolic activity, making it catabolic. Nutrition processes that involve metabolic activity include autotrophic nutrition and heterotrophic nutrition. Autotrophs include plants, algae and bacteria and rely on sunlight to change inorganic molecules such as water into smaller, organic molecules; this is known as photosynthesis. In heterotrophic nutrition, energy is taken from organic molecules and broken down to form even smaller molecules, and the food molecules come from autotrophs.

The metabolism of an organism defines which substances it will find nutritious and which ones will be poisonous. Metabolic rate also plays a strong factor in determining how much food an organism requires. Internal metabolic pathways are similar, even across species. The similarities are due to the efficiency of the pathways and the fact that they continue to evolve with species.

The Health Board 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

By anon991647 — On Jul 06, 2015

Why then are diets even allowed.

By stolaf23 — On Feb 25, 2011

Every person's metabolic rate is a little different, which is another reason why diets never have the same effect for everyone. In human activity, there are some rules that seem to hold for determining someone's caloric needs, but even that is still not strongly proven one way or the other. No one else can tell you what your body can metabolize and how much you can eat without gaining weight- it's something people have to sort of figure out.

By watson42 — On Feb 24, 2011

Metabolism isn't just about dieting and weight loss. It is about energy, which is why so many nutrition experts these days are trying to discourage dieting for people trying to lose weight. When you "diet", you rob your body of the nutrients it needs to metabolize properly, and the metabolic reactions in that case can often be the reverse of what you want- your body will hold on to its fat because it thinks you are going into starvation.

The Health Board, in your inbox

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

The Health Board, in your inbox

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