Carl & Gerty Cori Change the Face of Medicine

In brilliant collaboration, Carl and Gerty Cori studied how the body metabolizes glucose and advanced the understanding of how the body produces and stores energy. Their findings were particularly useful in the development of treatments for diabetes. They were awarded the Noble Prize for their discovery of how glycogen (animal starch) – a derivative of glucose – is broken down and resynthesized in the body, for use as a store and source of energy.

cori cycleThe pair were interested in how the body utilizes energy. The couple spent more than three decades exploring how the human body metabolizes glucose. It was known in the 1920s that faulty sugar metabolism could lead to diabetes, and it was also known that insulin kept the disease in check.

The effect of insulin on blood sugar levels had been observed, but scientists did not understand the biochemical mechanism behind insulin’s effect or how carbohydrates were metabolized. In 1929, the couple described what is now known as the Cori cycle; an important part of metabolism. To put it simply, lactic acid forms when we use our muscles, which is then converted into glycogen in the liver. Glycogen, in turn, is converted into glucose, which is absorbed by muscle cells.

The Cori Cycle

cori cycleThe Cori Cycle refers to the metabolic pathway in which lactate produced by anaerobic glycolysis in the muscles moves via the blood stream to the liver where it it is converted to blood glucose and glycogen. High intensity exercise will mostly get it’s energy or ATP from the pathway of the glycolitic system.  Less intense activity will receive its energy or ATP from the aerobic pathway utilizing the Krebs cycle.

When utilizing the glycolitic system, cycle after cycle, lactate will start to build up.  Lactate from the glycolitic system will diffuse from the muscles into the bloodstream.  It will then be transported into the liver.  In the liver it is converted from lactate back to pyruvate back to glucose, which is then available to the muscles again for energy, this is called gluconeogenesis.  The whole process is called the Cori Cycle.

The more you train with high intensity exercise, the more capable the enzymes and transporters become that are needed for the Cori Cycle.  Your liver gets better at using the lactate, not more efficient (it still needs the same amount of ATP to run the Cori Cycle) but it will do the cycle faster.

Gerty Cori Biography

carl & gerty cori Gerty Radnitz was born in Prague in what was then Austria-Hungary. She received her PhD in medicine from the German University of Prague’s Medical School in 1920. It was here that she met fellow classmate, Carl Ferdinand Cori, whom she married later that same year.

The couple moved to Buffalo, New York in 1922 and began researching metabolic mechanisms. As a woman, Gerty Cori was employed on much less favorable terms than her husband and encountered other forms of gender discrimination throughout her career.

The couple moved to Washington University in St. Louis in 1931 after both were offered positions there. When the Coris were hired at Washington University, she received one-tenth Carl’s salary, even though they were equal partners in the laboratory.

Gerty and her husband continued to investigate how glycogen is broken down into glucose and in 1939 were able to both identify the enzyme that initiates the decomposition and also to use the process to create glycogen in a test tube.

She became full professor in 1947, the same year that she and Carl were awarded the Nobel Prize “for their discovery of the course of the catalytic conversion of glycogen.” She was the first American woman to win the Nobel Prize in Science.

Around this time Gerty was diagnosed with myelosclerosis, a disease of the bone marrow. She died in 1957 at the age of 61.

Bring it Home

Try this hands-on lab from Amy Brown Science to discover The Use of Glucose in Cellular Respiration

Enjoy the Carl and Gerty Cori and Carbohydrate Metabolism commemorative booklet produced by the National Historic Chemical Landmarks program of the American Chemical Society in 2004.

Read about the dip-and-read test strips developed by Helen Free and her husband, Al. Originally designed to test for glucose in urine, the test strips were such an advance that researchers have since combined 10 urine tests to check for ailments like liver failure, urinary tract infections, and others—onto one plastic stick.

Learn more about our digestive system with these hands-on enzyme labs.

Investigate What Types of Food Contain Starch and Protein?

Building Macromolecule is a paper-scissors-tape activity used to help students envision the process of synthesis, building macromolecules out of smaller subunits.

Science Milestones

Visit my Science Milestones page to learn more about scientists whose discoveries and advancements have made a significant difference in our lives or who have advanced our understanding of the world around us.

Interested in learning about others who were born in the month of August? Hop over to Birthday Lessons in August to read posts by other iHomeschool Network bloggers.

 

Science Milestones: The Art and Science of Rube Goldberg

Rube Goldberg was a famous cartoonist who took simple and compound machines which are meant to make tasks easier, and made them overly complex. His cartoons depicted complex machines that worked in an indirect and convoluted way, such as the “Self-Operating Napkin”.

Art and Science of Rube Goldberg @EvaVarga.net

As you raise spoon of soup (A) to your mouth it pulls string (B), thereby jerking ladle (C) which throws cracker (D) past parrot (E). Parrot jumps after cracker and perch (F) tilts, upsetting seeds (G) into pail (H). Extra weight in pail pulls cord (I) which opens and lights automatic cigar lighter (J), setting off sky-rocket (K), which causes sickle (L) to cut string (M) and allow pendulum with attached napkin to swing back and forth thereby wiping off your chin.

Rube Goldberg Physics

When Goldberg showed his “Self-Operating Napkin” machine to his friend, his friend said it would not work. Using what you know about mechanical advantage and work, prove to Goldberg’s friend that the invention will actually work.

Work (in Joules, J) = Force (Newtons, J) x Distance (m)

Mechanical Advantage of a Lever = Distance from fulcrum to the applied force / Distance from fulcrum to weight lifted

You raise your spoon of soup 0.15 meters with 2 Newtons of force. How much work did you do?

The spoon pulls a string as you move it. How much work is transferred?

The string jerks the ladle, which is a lever. The string is attached 10 cm from the fulcrum and the force is applied 0.5 m from the fulcrum. What is the mechanical advantage?

The spoon throws a cracker past a parrot. The parrot jumps after the cracker, applying force to the perch he is sitting on. The perch spins around throwing the seeds into a pail. The perch is another lever. It has a mechanical advantage of 2. If it would take 0.5 J of work to move the seeds 0.1m without the lever, how much force will be needed with the lever?

The extra weight in the pail pulls a cord, which goes around a pulley and opens and lights an automatic cigar lighter. If the pail can apply 3 N of force to the cord, and the pulley system has a mechanical advantage of 2, how much total force can be applied to the match?

The match sets off the rocket, which causes a sickle to cut the string, allowing a pendulum with attached napkin to swing back and forth thereby wiping off your chin. If 3 N of force is needed to strike the match, will the system work?

Discover the amazing resources and contests at Rube Goldberg.

Biography

The Art and Science of Rube Goldberg @EvaVarga.netReuben Lucius “Rube” Goldberg was born on July 4, 1883, in San Francisco, California. He loved to draw and received some basic art instruction when he worked with a sign painter as a young teen. Rather than pursue a career in art, though, he followed his father’s advice and attended the University of California at Berkeley, where he earned his degree in engineering.

Mapping out sewer pipes and water mains in San Francisco didn’t hold Rube’s interest for long, though. He began creating cartoons for local San Francisco papers. He eventually moved to New York where he landed a job as a cartoonist for the Evening Mail.

He used his engineering background to create funny cartoons featuring complicated machines that were described as new inventions to accomplish easy, straightforward tasks through a series of convoluted steps involving chain reactions. The public quickly fell in love with Rube’s inventions.

His work became popular nationwide, as his cartoons were syndicated in hundreds of newspapers across the country. The art world also loved his works, some of which were displayed in the Museum of Modern Art in New York City. Rube even made it to Hollywood, where his move script “Soup to Nuts” introduced a trio who would soon become famous as the Three Stooges.

Bring It Home

Check out the following activities to learn more about Rube Goldberg and his work:

Dive a little deeper into the history by watching this video that explores the man behind the machines.

If you have a smartphone or a tablet, you can purchase and download Rube Works, a fun game that challenges you to build a virtual Rube Goldberg machine.

Make your own homemade Rube Goldberg machine! Check out Make a Rube Goldberg Machine for ideas to help you get started.

A Rube Goldberg culminating project will be included in the Physics Logic: Simple Machines & Laws of Motion curriculum to be released soon.

Science MilestonesYou may also be interested in learning about other inventors and scientists who have made an impact in our lives.

The bloggers of the iHomeschool Network have teamed up to create fun and original unit studies on fascinating people who were born in July.

The Silent Killer: Ecology Lessons with Rachel Carson

Ecology Lessons with Rachel Carson @EvaVarga.netThis post contains affiliate links.

Marine biologist and author Rachel Carson, whose writing on pesticides helped to launch the modern environmental movement, was born on 27th of May in 1907 in Springdale, Pennsylvania. Carson published her famous work Silent Spring in 1962 which documented the dangers of indiscriminate use of synthetic pesticides, especially on bird populations. Though its publication was met with strong opposition from the chemical industry, the scientific community largely supported her conclusions. Silent Spring also served as a rallying point for the young environment movement just gaining momentum at the time of its publication.

In nature nothing exists alone.

The book fueled public interest in environmental and public health issues and, within a few years, the Nixon Administration formed the Environmental Protection Agency. Much of the EPA’s early work focused on issues raised by Carson’s work such as a 1972 law regulating pesticides and a US ban on the agricultural use of DDT.

Biography

Rachel CarsonRachel grew up in a tiny, wooden house with no electricity, heat or plumbing. As a young girl, she was fascinated with the outside world. She spent a great deal of time in the woods and beside streams learning the names of birds, insects, and flowers.

Rachel’s best friend was her mother, Maria Carson, with whom she enjoyed taking long walks with in their nearby woods. Maria had been a teacher before she married and she taught Rachel the names of plants, birds, insects, and animals they encountered. It didn’t take long before Rachel was able to identify dozens of wild things.

Those who contemplate the beauty of the earth find resources of strength that will endure as long as life lasts.

In Rachel’s second year of college, she took a biology course that sparked her interest in this area. She graduated from college with honors and decided to specialize in Marine Biology- the study of animal life in the ocean. In 1929, she won a full scholarship to John Hopkins University in Baltimore, Maryland to obtain her graduate degree in this field of study.

After graduating from Johns Hopkins in 1932 (MA in Zoology), she began a career in the federal service as a scientist and editor and rose to become Editor-in-Chief of all publications for the U. S. Fish and Wildlife Service.

In addition to the well known Silent Spring, she wrote several other articles designed to teach people about the wonder and beauty of the living world, including “Help Your Child to Wonder,” (1956) and “Our Ever-Changing Shore” (1957). Woven throughout her writing was the view that human beings were but one part of nature distinguished primarily by their power to alter it, in some cases irreversibly.

Man is a part of nature, and his war against nature is inevitably a war against himself.

Rachel Carson died in 1964 after a long battle against breast cancer. Her witness for the beauty and integrity of life continues to inspire new generations to protect the living world and all its creatures.

Ecology Lessons with Rachel Carson @EvaVarga.netBring It Home

With Rachel Carson as a guide, students can learn how environmental concerns affect their lives and community. High students should be encouraged to read Silent Spring. Middle school students may be more comfortable reading selected chapters; I recommend the first chapter “A Fable for Tomorrow,” which can be previewed online. [Tip: Do a search on the chapter title to find the full text, which is available from various sources.]

  • Read a biography:
  • Watch the compelling documentary film American Experience: Rachel Carson’s Silent Spring
  • Have the students write a short story about how they think the world will change in the next ten years.
  • Ask students how they perceive our oceans being polluted today and let them come up with ways we can contribute to the efforts of protecting our sea life.
  • Have students research the toxic effects of DDT on the body, where it might be used today, and what alternatives can be used in its place.
  • Ask students to make a booklet on ways to live that can reduce an individual’s impact on the environment. Examples of subjects include saving water, gardening, cleaning and maintenance around the house, your car, renewable energy, air pollution, and the environmentally aware consumer.
  • Interview a person who has lived in the community for 30 years or longer. Suggested questions might include:
    • How has our community’s environment changed over the time you have lived here?
    • What was the environment of our community like when you first lived here?
    • What changes made the greatest impact on the environment?
    • Have the changes been for the better? Why do you feel this way?
    • In retrospect, compare the benefits and detriments of the impact of people on the land.

What about us? Can we avoid the “silent spring” that Carson predicted? In the 53 years since Silent Spring first appeared, people have grown far more aware of our impact on the environment. But we still use many potentially deadly chemicals.”There remains, in this space-age universe,” wrote Rachel Carson, “the possibility that man’s way is not always best.” We would do well to remember her warning.

Science Milestones