Metabolism is a vital process that keeps living organisms functioning. It balances energy production and consumption through catabolism and anabolism.

Definition of metabolism

Metabolism refers to all the chemical reactions that take place inside a living organism. These reactions help convert nutrients into energy and into materials needed for growth, repair, and cell maintenance.

Types of metabolism

1. Catabolism

Catabolism includes all breakdown reactions.
It breaks complex molecules (carbohydrates, lipids, proteins) into simpler ones while releasing energy.

Example: breakdown of glucose to produce energy.

2. Anabolism

Anabolism includes all building reactions.
It uses energy to build complex molecules needed by the body.

Example: protein synthesis from amino acids.

Functions of metabolism

Metabolism is essential for:

• producing energy
• supporting growth
• repairing tissues
• maintaining body temperature
• ensuring organ function

Factors affecting metabolism

Metabolism can be influenced by:

• age
• gender
• physical activity
• diet
• hormones (such as thyroxine)

Metabolism and energy

The energy produced by metabolism is stored and used in the form of ATP (adenosine triphosphate), which is the main energy source of cells.