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Films · Biology · Molecular genetics

Explainer film · Molecular genetics

One Letter Too Many

The end

One Letter Too Many

A single swapped letter puts valine where glutamic acid belongs, haemoglobin clumps into fibres without oxygen, and the cells sickle. Two copies cause disease, one copy protects against malaria, and that is why the allele survives.

Chapter 1 · A recipe in groups of three

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One Letter Too Many

Biology · Molecular genetics

NewOct 18, 2026 · 4 chapters

An explainer film in four chapters: how triplets of letters become a protein, what a single swapped letter does to haemoglobin, why red blood cells turn into sickles, and why the allele still does not die out: in a single dose it protects against malaria. Pause anywhere and ask.

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