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Circadian Rhythms

Last week the 2017 Nobel Prize winners in six different categories were announced. This month I continue to write about the winning projects in the science fields – physics, medicine & physiology and chemistry.

The 2017 Nobel Prize in chemistry was awarded to Jeffrey Hall, Michael Rosbash, and Michael Young for discovering the genetic and cellular mechanism behind circadian rhythms

Circadian is made from circa the Latin word meaning “around” and dian meaning “a day.” A circadian rhythm is the 24 hour cycle that plants and animals go through each day. There is time for rest, time for being alert. It turns out that the cycle is regulated by proteins created by the DNA in our cells, although light and temperature can effect your circadian rhythms as well.

You can learn more about the exact cellular mechanism discovered by this year’s Nobel winners but it is quite easy to learn about circadian rhythms on a bigger, organism scale.Here are just a couple of ideas:

  • Grow some bean seeds in a sunny window and observe the motion of their leaves during a day. Put some of the bean plants in a dark closet but continue to watch the motion of the bean plant’s leaves. Do they follow the same cycle even without sunlight? Or try this with Mimosa plants, which close up their leaves at night.
  • Monitor your own circadian rhythms. Take your temperature and blood pressure every hour for a couple of days. Do you see a pattern? What times of day is your blood pressure and temperature highest? Lowest?
  • (This one is best done when school is out) Does your body know when to wake up? Instead of using an alarm clock or having someone wake you up, keep track of what time your body wakes up on its own in the morning. What time do you go to bed? More on sleep patterns and chronotype here.

Even astronauts on the International Space Station have to deal with changes in circadian rhythms since in their world the sun rises or sets every 90 minutes!