Which term is defined as the process of combining small molecules to form larger ones?

The term that describes the process of combining small molecules to form larger ones is anabolism. Anabolism is a type of metabolic pathway that focuses on building complex molecules from simpler ones, often requiring energy input. This process is essential for growth, repair, and the production of cellular structures such as proteins and nucleic acids. Anabolic reactions play a critical role in processes such as muscle growth, tissue repair, and the synthesis of hormones.

Catabolism, in contrast, refers to the breakdown of large molecules into smaller ones, releasing energy in the process. Metabolism encompasses both anabolic and catabolic pathways; therefore, it includes a broader range of biochemical processes. Fermentation is a specific metabolic process that converts sugars into acids, gases, or alcohol in an anaerobic environment, and is not specifically about combining molecules. Understanding these distinctions clarifies why anabolism is the correct choice in this context.