Metabolism is the term used to describe all the chemical reactions that take place inside living cells to keep an organism alive and functioning.
It involves two main types of processes:
- Catabolism (Breaking down):
- In catabolic reactions, large molecules like carbohydrates, fats, and proteins are broken down into smaller molecules.
- This process releases energy, which the body uses to make ATP — the energy currency of the cell.
- Example: Breaking down glucose during cellular respiration to produce ATP.
- Anabolism (Building up):
- In anabolic reactions, the body uses energy to build complex molecules from smaller ones.
- These reactions are needed for growth, repair, and maintenance.
- Example: Making proteins from amino acids or DNA from nucleotides.
- Energy Flow:
- The energy released from catabolism is used to power anabolic processes, keeping the body’s systems in balance.
In short:
Metabolism is the sum of all chemical reactions in the body — it includes both the breakdown of food to release energy (catabolism) and the use of energy to build and repair cells (anabolism). It’s what keeps every living organism alive, growing, and functioning properly.