Comparing the Genome, Transcriptome, and Proteome
- Every cell in an organism contains the same genome (complete set of genetic instructions).
- However, no cell expresses all of its genes.
The pattern of gene expression in a cell determines how it differentiates.
The Genome, Transcriptome, and Proteome
- Genome: The complete set of DNA in a cell (same in all cells).
- Transcriptome: The complete set of RNA molecules transcribed from the genome at a specific time (varies between cells).
- Proteome: The complete set of proteins produced by a cell at a specific time (varies between cells).
| Feature | Genome | Transcriptome | Proteome |
|---|---|---|---|
| Definition | All genetic material in a cell | All RNA molecules transcribed | All proteins produced |
| Variability | Consistent across cells | Varies between cells and over time | Varies between cells and over time |
| Components | DNA (coding and non-coding) | mRNA, rRNA, tRNA, etc. | Functional proteins |
| Stability | Stable throughout life | Dynamic and responsive | Dynamic and responsive |
| Function | Blueprint for all cellular functions | Reflects active gene expression | Determines cell function |
Why Do Cells Differ?
- Selective gene expression: Cells only transcribe and translate the genes needed for their specific functions.
- Cell differentiation: Specialized cells (e.g., muscle cells, neurons) express unique sets of genes to perform specific roles.
- Why do all cells in an organism have the same genome, yet differ in structure and function?
- Explain how the pattern of gene expression determines cell differentiation.
