Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a stimulus indicating damage to its DNA from environmental insults or errors during metabolism.

The chemical reactions and pathways resulting in the breakdown of glyoxylate, the anion of glyoxylic acid, HOC-COOH.

The pathways by which allantoin is processed and converted to ureidoglycolate, and then into metabolically useful substrates. E. coli are able to utilize allantoin as a sole nitrogen source under anaerobic conditions by converting it to ureidoglycolate; this may be further metabolized to produce glyoxylate and thence 3-phosphoglycerate, or alternatively oxidized to oxolureate, which can converted into oxamate and carbamoylphosphate. This may then be further metabolized to CO2, NH4+ and ATP.