MK ATLAS· Science Atlas

Dorothy Hodgkin

Can you see the shape of a molecule?

Chemistry· 1964· Oxford · Dorothy Hodgkin· Build

1min readUpdated 2026-09-29

That time, that place

Fire X-rays at a molecule and the scattered light forms a pattern that encodes how the atoms are arranged.

The difficulty is that working backward from pattern to arrangement takes staggering computation. Before computers, that meant years of work by hand.

Why this question

Hodgkin chose the hard side.

Her first great target was penicillin. Mass production was urgent in wartime, and without the structure it could be neither synthesized nor improved. Many chemists thought the structure impossible: it contained a four-membered ring, and such a ring was supposed to be far too strained to exist.

What was found

She showed the ring is genuinely there. Precisely because it is strained, it can attack the enzyme that builds bacterial cell walls. The structure was the mechanism.

Next came vitamin B12 — a molecule of 181 atoms, solved over five years.

And then insulin. She began on it in 1934 and completed the structure in 1969. Thirty-four years. She had to wait for crystallographic technique to improve, and while waiting she solved other things and pushed the technique forward herself.

The old idea

The atomic arrangement of large biological molecules could not be determined

The evidence

Atomic maps computed backward from diffraction patterns

What followed

She worked all her life with hands badly deformed by rheumatoid arthritis. When she won the Nobel, a British paper headlined it as a prize for an Oxford housewife