01. The Blueprint Setup
Meet the Architect
I am RNA Polymerase! I look for the Transcription Unit.
The Three Zones
1. Promoter: Landing strip.
2. Structural Gene: The code.
3. Terminator: Stop sign.
02. The Polarity Rule
5' to 3' Only!
I build RNA in 5' → 3'. I read the 3' → 5' strand.
Naming Paradox
The read strand is the Template. The other is the Coding Strand.
03. Location Matters
Upstream vs Downstream
Positions are based on the Coding Strand. Promoter is Upstream (5').
What is a Gene?
A functional unit coding for polypeptide, rRNA, or tRNA.
04. Eukaryotes vs Bacteria
Bacteria
Genes are Polycistronic (Multiple proteins).
Eukaryotes
Genes are Monocistronic and Split (Exons + Introns).
05. Starting the Engine
Sigma Factor (σ)
I need the Sigma Factor to find the Promoter.
Transient
Sigma leaves once elongation starts.
06. The Finish Line
Rho Factor (ρ)
I need the Rho Factor to stop.
Coupling
In bacteria, translation starts while transcription is still happening!
Quiz Sector: Phase 1
Basics Check
Remember the orientation! Upstream means towards the 5' end of the coding strand. Green = Correct.
Quiz Sector: Phase 2
Advanced Check
Recall the difference between simple bacteria and complex eukaryotes. Introns "interrupt" the code!
Quiz Sector: Final Phase
Process Check
Termination and Coupling are the final steps. If you ace this, you're a Transcription Master!
CLASSIFIED SUMMARY
| FEATURE | PROKARYOTES | EUKARYOTES |
|---|---|---|
| Gene Type | Polycistronic | Monocistronic (Split) |
| Initiation | Sigma Factor required | Transcription Factors |
| Coupling | Yes (Translation starts early) | No (Nucleus separates them) |
| Processing | None needed | Splicing, Capping, Tailing |
| RNA Pol | Single type for all RNA | 3 Types (Pol I, II, III) |