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MCAT - Biology - Molecular BiologyLive tournament10 tasks

Translation Tournament

Two onboarding diagrams place translation inside protein metabolism. Then eight MCAT-DoK rounds: Met vs fMet initiation, the streptomycin / gentamicin / chloramphenicol / tetracycline / macrolide map, the A/P/E ribosome cycle, the eIF/eEF/eRF cast, the genetic code's wobble + degeneracy, the 2 GTP per peptide bond, and diphtheria toxin's eEF2 target.

Step 1 of 3 - The bigger pictureTranslation Tournament

Where the Translation fits in Metabolism of proteins

Translation is the cytosolic decoding step of the central dogma - a ribozyme catalyzes peptide bond formation while the mRNA's sequence dictates amino acid order via tRNA wobble pairing. To enter the tournament, click the highlighted Translation box.

SFTPA1 HEXAMER LIPIDS RIBOSOME GENERIC PROTEIN APP LONP1 XXX/YYY PROTEIN FOLDING METHIONINE SULFOXIDE L-Met XXX/YYY PROTEIN REPAIR XXX/YYY SURFACTANT METABOLISM Ub Ub XXX/YYY POST-TRANSLATIONAL PROTEIN MODIFICATION XXX/YYY AMYLOID FIBER FORMATION INSULIN PEPTIDE HORMONE METABOLISM XXX/YYY IGF1 IGFBP4 REGULATION OF INSULIN-LIKE GROWTH FACTOR (IGF) TRANSPORT AND UPTAKE BY INSULIN-LIKE GROWTH FACTOR BINDING PROTEINS (IGFBPS) XXX/YYY XXX/YYY MITOCHONDRIAL PROTEIN DEGRADATION XXX/YYY TRANSLATION

Click the highlighted Translation 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.

1

The Bigger Picture

Locate translation inside Reactome's Metabolism of Proteins overview.

2

Whole-Pathway Overview

Pan and zoom the WikiPathways translation figure before you play.

3

Fill in the Blank

Recall that eukaryotes initiate with Met (not fMet) on Met-tRNAi.

4

Disruptor

Walk streptomycin's mechanism and why human cytosolic ribosomes are spared.

5

Sequence Ordering

Walk eukaryotic initiation -> elongation -> termination with the right factors.

6

Match the Pairs

Pair eIF2 / eIF4F / eEF1A / eEF2 / eRF1+eRF3 with their precise jobs.

7

Numeric Input

Recall the 2 GTP per amino acid added during elongation.

8

Select All That Apply

Identify true facts about the genetic code (degeneracy, wobble, near-universality).

9

Odd One Out

Spot the DNA template strand among the genuine ribosome substrates.

10

Diphtheria Toxin

Explain why a single eEF2-targeting toxin molecule can kill a cell.

Public leaderboard

Your score posts to a global, persistent leaderboard scored by points first, time as tiebreaker.

Translation in 60 seconds

Eukaryotic ribosome = 80S = 40S + 60S; prokaryotic = 70S = 30S + 50S. Three sites: A (Aminoacyl, new tRNA arrives), P (Peptidyl, growing chain), E (Exit, empty tRNA leaves). Peptide bond formation is catalyzed by the 23S/28S rRNA - a ribozyme.

Initiation: 40S + Met-tRNAi + eIF2-GTP form the 43S complex; eIF4F recruits it to the 5' cap; scanning to AUG (Kozak context); 60S joins. Elongation: eEF1A-GTP delivers aa-tRNA to A site; peptidyl transferase forms the bond; eEF2-GTP translocates by one codon. Termination: eRF1 reads stop codons; eRF3-GTP releases the peptide.

Antibiotic targets (high yield): streptomycin / aminoglycosides bind 30S and cause misreading; tetracyclines block aa-tRNA at 30S A site; chloramphenicol blocks 50S peptidyl transferase; macrolides block 50S translocation; clindamycin / linezolid also 50S. All target bacterial-specific subunits. Mitochondrial 70S-like ribosomes explain aminoglycoside ototoxicity.

Energy: 2 ATP equivalents to charge each tRNA + 2 GTP per added amino acid = ~4 high-energy phosphates per peptide bond. Translation is one of the most energetically expensive cellular processes.

FAQ

Why is the genetic code degenerate?

64 codons code for 20 amino acids + 3 stops, so most amino acids have multiple codons. Degeneracy buffers against point mutations - especially at the wobble (3rd) position, which often doesn't change the encoded amino acid. Met (AUG) and Trp (UGG) are the only single-codon amino acids.

How does diphtheria toxin work?

Diphtheria toxin's catalytic A subunit ADP-ribosylates a unique modified histidine (diphthamide) on host eEF2. eEF2 is the only protein in the cell with diphthamide - so the toxin is exquisitely specific. With eEF2 inactivated, the ribosome cannot translocate, all translation halts, and the cell dies. Pseudomonas exotoxin A uses the SAME mechanism.

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.