When an enzyme is degraded into its monomeric structural units, the monomers will be:

The correct answer is amino acids because enzymes are proteins, which are polymers made up of long chains of amino acids linked together by peptide bonds. When an enzyme is degraded or broken down, it undergoes a process called hydrolysis, where these peptide bonds are cleaved, leading to the release of individual amino acids. These amino acids can then be recycled for the synthesis of new proteins or utilized in various metabolic pathways.

The other options represent different classes of biomolecules rather than the structural units that make up proteins. Monosaccharides are the basic building blocks of carbohydrates, fatty acids are the components of lipids, and nucleotides are the units that make up nucleic acids like DNA and RNA. Hence, while these compounds are vital for numerous biological functions, they are not relevant to the question regarding the degradation of enzymes specifically.