"A change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a stimulus indicating lowered oxygen tension. Hypoxia, defined as a decline in O2 levels below normoxic levels of 20.8 - 20.95%, results in metabolic adaptation at both the cellular and organismal level [goid 1666] [pmid 15174142] [evidence IEP]; The covalent alteration of one or more amino acids occurring in proteins, peptides and nascent polypeptides (co-translational, post-translational modifications). Includes the modification of charged tRNAs that are destined to occur in a protein (pre-translation modification) [goid 6464] [pmid 1577494] [evidence NAS]; The process whose specific outcome is the progression of the epidermis over time, from its formation to the mature structure. The epidermis is the outer epithelial layer of a plant or animal, it may be a single layer that produces an extracellular material (e.g. the cuticle of arthropods) or a complex stratified squamous epithelium, as in the case of many vertebrate species [goid 8544] [pmid 8449506] [evidence IMP]; The process whose specific outcome is the progression of the epidermis over time, from its formation to the mature structure. The epidermis is the outer epithelial layer of a plant or animal, it may be a single layer that produces an extracellular material (e.g. the cuticle of arthropods) or a complex stratified squamous epithelium, as in the case of many vertebrate species [goid 8544] [pmid 1577494] [evidence TAS]; The chemical reactions and pathways involving a specific protein, rather than of proteins in general. Includes protein modification [goid 19538] [evidence IEA]; The chemical reactions and pathways resulting in the formation of hydroxylysine (5-hydroxy-2,6-diaminohexanoic acid), a chiral alpha-amino acid [goid 46947] [pmid 1577494] [evidence TAS]; The process of removal or addition of one or more electrons with or without the concomitant removal or addition of a proton or protons [goid 55114] [pmid 1577494] [evidence TAS]"