What is the proteome?

The proteome refers to the comprehensive set of proteins that are expressed by a particular cell, tissue, or organism at a given time under specific conditions. This term highlights the dynamic and variable nature of protein expression, which can change based on developmental stages, environmental conditions, and other factors.

By defining the proteome in this way, it emphasizes the functional aspects of proteins in biological processes. Each cell type can have a unique proteome that reflects its specific functions and roles within an organism. This concept is integral to the fields of genomics and proteomics, as understanding the proteome is essential for studying cellular functions and interactions, as well as for developing targeted therapies and personalized medicine approaches.

The other options address different concepts. A list of all possible enzymes would not capture the variability or specificity of protein expression in a given context, while a collection of different DNA sequences pertains to the genome, not the proteome. Finally, measuring protein activity involves assessing the function of proteins rather than defining what constitutes the proteome itself.