Red Pen Prep

Six labs · no signup

Guess first, then watch it happen.

Six pages built on the real equations. Change one thing and the molecules, the curve and the numbers move together, so the rule stops being a sentence you memorized.

Buffer Lab, as it looks when you open itAcid seriesBuffer LabTitrate a weak acid with NaOH. Halfway, pH lands on pKa; in your blood, about 20 HCO₃⁻ for every CO₂.Open it Enzyme Lab, as it looks when you open itEnzyme seriesEnzyme LabAdd a competitive or a noncompetitive inhibitor and watch Km, Vmax and the Lineweaver–Burk plot move.Open it Living Neuron Lab, as it looks when you open itPhysiologyLiving Neuron LabA 3D patch of membrane: push it, poison it with TTX, block K⁺, and watch the channels open and close.Open it Neuron Lab, as it looks when you open itPhysiologyNeuron LabThe 1952 Hodgkin–Huxley equations, live. Every click you hear is one action potential.Open it Spectrum Lab, as it looks when you open itChem/PhysSpectrum LabTap an element and hear its emission lines, kept in exact ratio. Then ΔE = hf.Open it CARS X-ray, as it looks when you open itCARSCARS X-rayA real passage with its voices, turns and hedges marked, and the line that settles each question.Open it

When you want the full course

3,122 MCAT questions. Every wrong answer named, and corrected in red.

  • All four sections with full passages and their tables
  • The X-ray lens on every CARS passage: turns, hedges, whose view, the point
  • The lesson before the passage: 83 passages open with their 30-second 3D lesson
  • 11 full-length exams and the Trap Bank, 155 drills on the traps that cost the most points
  • Every miss comes back 1, 3 and 7 days later, until it sticks

$299until Nov 30 · $600 from Dec 1

Founding price until November 30, then $600.

Get the Pass · $299Try a sample passage

30-day full refund, no questions asked.