Which term describes the set of proteins expressed by the genome at a given time?

• A. Genome
• B. Proteome
• C. Phenome
• D. Transcriptome

Answer: (B)

The concept being tested is the dynamic collection of proteins actually produced by a genome under specific conditions. This set of proteins expressed at a given time is called the proteome. It reflects what is functionally active in a cell or tissue at that moment, including different protein variants and post-translational modifications that arise after translation. In contrast, the genome is the full genetic blueprint, the transcriptome covers all RNA transcripts produced, and the phenome refers to the observable traits and features of an organism. Because the proteome represents the real functional molecules present under particular circumstances, it best fits the description of the proteins expressed by the genome at a given time.