Metabolism:

Metabolism is the set of biochemical reactions that occur in living organisms to maintain life. These processes allow organisms to grow and reproduce, maintain their structures and respond to their environments. Biochemical reactions in living organisms are essentially energy transfers. During metabolism, chemicals are transformed from one form to the other by enzymes. Enzymes are crucial to metabolism because they act as biocatalysts and speed up and regulate metabolic pathways.

Anabolism:

Anabolism is the total series of chemical reactions involved in the synthesis of compounds.

Catabolism:

Catabolism is the series of chemical reactions that break down larger molecules. Energy is released in catabolism and some of it is utilized in anabolism. Products of catabolism can be reassembled by anabolic processes into new molecules.