Transcription Tournament
Two onboarding diagrams place transcription inside gene expression. Then eight MCAT-DoK rounds: coding vs template strand, splice-site mutation consequences, mRNA biogenesis order, the regulatory cis-elements, Pol II elongation rate, α-amanitin's polymerase-discriminating mechanism, and the prokaryote-vs-eukaryote distinctions.
Where the RNA polymerase II transcription fits in Gene expression (transcription)
Eukaryotic transcription is split across three nuclear polymerases. Pol II makes mRNAs (and most snRNAs) and is the workhorse of protein-coding gene expression. To enter the tournament, click the highlighted RNA polymerase II transcription box.
Click the highlighted RNA polymerase II transcription box to continue.
What this tournament tests
Each task maps to a distinct MCAT cognitive demand. The first two orient you in the broader topology; the next eight test the high-yield mechanism, regulation, sequence and quantitative reasoning that consistently appear on test day.
The Bigger Picture
Locate Pol II inside Reactome's Gene Expression overview.
Whole-Pathway Overview
Pan and zoom the WikiPathways transcription figure before you play.
Fill in the Blank
Distinguish the coding (sense) strand from the template (antisense) strand.
Disruptor
Predict the impact of a 3' splice-site mutation on the mature mRNA.
Sequence Ordering
Order Pol II initiation -> capping -> splicing -> 3' cleavage -> poly-A -> export.
Match the Pairs
Pair TATA / enhancer / cap / poly-A / AAUAAA with their cis-regulatory roles.
Numeric Input
Recall Pol II elongates at ~50 nt/sec - and why DNA polymerase has to be ~20× faster.
Select All That Apply
Identify true facts about Pol II initiation, processing, and proofreading.
Odd One Out
Spot the prokaryotic Shine-Dalgarno among eukaryotic mRNA features.
α-Amanitin Mechanism
Explain why the death-cap mushroom toxin specifically kills hepatocytes.
Public leaderboard
Your score posts to a global, persistent leaderboard scored by points first, time as tiebreaker.
Eukaryotic transcription in 60 seconds
Three nuclear polymerases: Pol I (nucleolus, rRNA precursor), Pol II (nucleoplasm, mRNA + most snRNAs), Pol III (nucleoplasm, tRNA + 5S rRNA + U6 snRNA). α-Amanitin sensitivity sorts them: Pol II most, Pol III moderate, Pol I insensitive.
Initiation: Pol II + general transcription factors (TFIIA, TFIIB, TFIID with TBP, TFIIE, TFIIF, TFIIH) assemble at the promoter (TATA, Inr, DPE). TFIIH's helicase opens the bubble; its kinase phosphorylates the Pol II CTD to release it from the promoter. Enhancers can act over tens of kilobases through DNA looping.
Processing is co-transcriptional: 5' cap (7-methylguanosine) added to the first ~25 nt; introns spliced by the spliceosome (snRNPs U1/U2/U4/U5/U6, branch-point A); 3' cleavage at the AAUAAA signal; poly-A tail (~250 As) by poly-A polymerase. Mature mRNA is licensed for export by the cap-binding complex + EJC.
No proofreading: Pol II has backtracking + RNA cleavage (TFIIS-stimulated) but lacks a true 3' -> 5' exonuclease - so error rate (~10^-4) is much higher than DNA polymerase. That's OK because mRNA is short-lived and one bad mRNA doesn't mutate the genome.
FAQ
Why does α-amanitin kill liver and kidney cells specifically?
α-Amanitin is hepatotropic - it concentrates in liver via OATP1B3 transporters and is excreted through the kidneys. Both organs have actively transcribing Pol II, and amanitin's slow Pol II inhibition (binds the bridge helix, blocks translocation) causes Pol II depletion -> apoptosis -> hepatic and renal failure within 1-2 days.
What is the difference between coding and template strands?
The CODING (sense) strand has the same sequence as the mRNA (with T for U). The TEMPLATE (antisense) strand is what RNA polymerase actually reads (3' -> 5') to write mRNA (5' -> 3'). MCAT loves to ask which is which - if you have an mRNA, just rewrite U as T to get the coding strand.
Do I need an account to play?
No. The tournament is fully public. You get a randomized handle and your score posts to the public leaderboard at the bottom of this page.
Keep going
Ribosomes, codon-anticodon, antibiotic targets - the immediate downstream of transcription.
Replisome enzymes and the leading-vs-lagging strand logic.
Overview diagram: Reactome Pathway R-HSA-74160, licensed CC BY 4.0.