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.
The 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
The 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
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.
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.