STOCKHOLM (AP) — The Nobel Prize for Chemistry rewards researchers for major advances in studying the infinitesimal bits of material that are the building blocks of life.

Recent prizes have gone to scientists who developed molecular "machines" — molecules with controllable motions — and who mapped how cells repair damaged DNA, leading to improved cancer treatments.

The 2017 prize, worth 9 million kronor ($1.1 million), is being announced Wednesday by the Royal Swedish Academy of Sciences.

It's the third Nobel announced this week.

The medicine prize went to three Americans studying circadian rhythms: Jeffrey C. Hall, Michael Rosbash and Michael W. Young. The physics prize went to Rainer Weiss, Barry Barish and Kip Thorne for detecting gravitational waves.

The literature winner will be named Thursday and the peace prize will be announced Friday.