Metabolism

Metabolism is the group of chemical processes that take place inside living things to keep them alive. These processes allow organisms to use energy from food, repair cells, grow, and carry out basic life functions. Every plant, animal, and microorganism has metabolism. Without it, living things would not be able to move, grow, or stay healthy.

Metabolism is often described in two main parts: catabolism and anabolism. Catabolism breaks down food or stored materials to release energy. For example, when the body breaks down sugars or fats, it produces energy that muscles and organs can use. Anabolism uses energy to build or repair parts of the body, such as making new proteins to replace old cells. These two processes work together so the body can use and store energy as needed.

Metabolism depends on nutrients from food. When people eat, the body breaks food into smaller substances like glucose, amino acids, and fatty acids. These substances enter the bloodstream and move to cells, where chemical reactions occur. Cells use oxygen to help release energy from these nutrients. This energy supports activities such as breathing, thinking, moving, and maintaining body temperature.

Different organisms have different metabolic needs. For example, some animals require large amounts of energy to move quickly or stay warm, while others use energy more slowly. Plants have metabolism too, using sunlight, water, and carbon dioxide to make their own food through photosynthesis. Microorganisms such as bacteria also have metabolic processes that help them grow and survive in many environments.

Metabolism can be influenced by factors such as age, size, and activity level. Growing children, for example, may have higher metabolic needs because their bodies are building new tissues. When the body is active, such as during exercise or play, it uses more energy, and metabolic processes speed up to supply it. When the body is resting, metabolism continues, but it may use energy at a slower rate.

Scientists study metabolism to understand how living things use energy and how different processes work together inside the body. By learning more about metabolism, they can describe how cells function, how nutrients support life, and how bodies change during growth and daily activities.