Regulation of Gene Expression
This lesson connects molecular mechanisms, cell behavior and biological evidence. Instead of memorizing isolated terms, follow what changes, what is measured, where the process occurs and why the outcome matters to a living system.
Big idea
Regulatory proteins bind DNA sequences and influence whether RNA polymerase initiates transcription. Cell signals activate pathways that change transcription-factor activity and gene expression.
Learning goals
- Promoters and transcription factors: Regulatory proteins bind DNA sequences and influence whether RNA polymerase initiates transcription.
- Signal-responsive control: Cell signals activate pathways that change transcription-factor activity and gene expression.
- Chromatin and epigenetics: DNA packaging and chemical marks alter access to genes without changing the base sequence.
- Post-transcriptional regulation: RNA splicing, stability, localization and small RNAs control which messages are translated.
- Differential expression: Cells with the same genome become different because they activate different sets of genes.
Core concepts
1. Promoters and transcription factors
Regulatory proteins bind DNA sequences and influence whether RNA polymerase initiates transcription.
Observation or application: An activator at an enhancer helps assemble the transcription machinery at a promoter.
2. Signal-responsive control
Cell signals activate pathways that change transcription-factor activity and gene expression.
Observation or application: A hormone-triggered phosphorylation event switches a target gene on.