Here's a breakdown:

* Anabolism is one of the two main types of metabolism (the other being catabolism).

* It involves building up complex molecules from simpler ones, requiring energy.

* This process is essential for growth, repair, and maintenance of tissues.

Here's how it works in the context of building tissue:

1. Small molecules like amino acids (for proteins), fatty acids (for lipids), and sugars (for carbohydrates) are absorbed from the environment or broken down from food.

2. Energy is supplied by ATP (adenosine triphosphate), the energy currency of cells.

3. Enzymes act as catalysts to facilitate the chemical reactions that bind the smaller molecules together into larger ones.

4. These larger molecules then assemble into macromolecules like proteins, fats, and carbohydrates.

5. These macromolecules form the building blocks of cells, which in turn form tissues.

Examples:

* Protein synthesis: Amino acids are linked together to form proteins, which are essential for structural support, muscle function, and enzyme activity.

* Lipid synthesis: Fatty acids and glycerol are combined to form fats, which store energy and form cell membranes.

* Carbohydrate synthesis: Glucose is used to create glycogen, which is stored as energy reserves in the liver and muscles.

In short, anabolism is the process by which organisms use simple molecules and energy to build the complex structures needed for growth, repair, and overall functioning.