Metabolism can be bisected into two subcategories:

(a) catabolism and anabolism.
(b) takes complex organic molecules and breaks them down into simpler molecules; this is often accompanied by the of energy.
(c) builds up biomolecules from simpler substances; this is often accompanied by the of energy.

A (catabolism and Anabolism)

Explanation:

Metabolic pathway are basically divided into two categories.

1. Catabolic

2. Anabolic

Catabolic (degradation) pathways, where energy rich complex macramolecules are degraded into smaller molecules. Energy released during this is trapped as chemical energy, usually as ATP.

Anabolic (biosynthesis) pathways. The cells synthesize complex molecules from simple precursors. This needs energy.

straight or amphibians are homeothermic to thermal