Which amino acids are used in the test for decarboxylase?

The correct answer, which identifies lysine, arginine, and ornithine as the amino acids used in the test for decarboxylase, reflects the principles of amino acid metabolism. In decarboxylation, specific amino acids undergo enzymatic reaction that removes the carboxyl group.

Lysine, arginine, and ornithine are key substrates in this process because they possess the appropriate structures for decarboxylation reactions. When ferried through decarboxylase enzymes, these amino acids convert to biogenic amines, which play important roles in various physiological functions. For example, lysine decarboxylation yields cadaverine, while arginine leads to the formation of agmatine, and ornithine can yield putrescine.

The other choices include amino acids that are not directly involved in standard decarboxylase tests or do not serve as primary substrates for the key decarboxylation reactions measured in typical microbiological tests. Thus, the focus on lysine, arginine, and ornithine captures the essential components of this metabolic process and the utility of these amino acids in identifying and understanding microbial decarboxylase activity.