LIFE SCIENCE

Detailed explanation-1: -anabolism, also called biosynthesis, the sequences of enzyme-catalyzed reactions by which relatively complex molecules are formed in living cells from nutrients with relatively simple structures.

Detailed explanation-2: -Catabolic reactions break down complex chemicals into simpler ones and are associated with energy release. Anabolic processes build complex molecules out of simpler ones and require energy. In studying energy, the term system refers to the matter and environment involved in energy transfers.

Detailed explanation-3: -A chemical synthesis usually involves the breaking of existing bonds and the formation of new ones. Synthesis of a complex molecule may involve a considerable number of individual reactions leading in sequence from available starting materials to the desired end product.