The synthesis of complex molecules from simpler ones with the input of energy is called anabolism.

Here's a breakdown:

* Anabolism: A process in metabolism where simpler molecules are combined to form more complex molecules, requiring energy input. This is often referred to as "building up".

* Catabolism: The opposite of anabolism, where complex molecules are broken down into simpler ones, releasing energy. This is often referred to as "breaking down".

Examples of anabolic processes:

* Protein synthesis: Amino acids are combined to form proteins.

* Photosynthesis: Carbon dioxide and water are used to create glucose in plants.

* Glycogenesis: Glucose is converted into glycogen for storage.

Let me know if you have any other questions!