What is defined as all the proteins that a cell makes at a given time?

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

Answer: (B)

The term that defines all the proteins that a cell makes at a given time is known as the proteome. This concept encompasses the entire set of proteins expressed by the genome of an organism under specific conditions. The proteome is dynamic and can vary depending on factors such as developmental stage, environmental conditions, and the specific type of cell. This variability allows cells to respond to different stimuli and perform functions necessary for survival and adaptation.

In a broader context, while the genome refers to all of the genetic material (DNA) in an organism, the transcriptome represents the complete set of RNA transcripts produced from the genome at any given time. The phenotype encompasses the observable characteristics or traits of an organism, influenced by both genetic and environmental factors. Thus, the correct identification of the proteome emphasizes the specific focus on proteins, distinguishing it from other related concepts in molecular biology.