How is a 'proeome' defined in biological terms?

The term 'proteome' refers to all proteins expressed by a cell at a given time. This concept encompasses not just the total number of proteins present, but also variations in expression levels and the post-translational modifications that can alter the function and activity of proteins. The proteome can vary greatly between different cell types, stages of development, and environmental conditions, reflecting a dynamic and responsive biological system. Understanding the proteome is key in fields like systems biology and proteomics, as it provides insights into cellular functions and regulations. This contrasts with other concepts such as the genome, which refers to the complete set of DNA in an organism, or genetic information summarized in different contexts, making the definition of 'proteome' specifically focused on protein expression crucial.