key term - Cori Cycle

Definition

The Cori Cycle is a metabolic pathway that describes the process of converting lactate produced during anaerobic glycolysis in muscles back into glucose in the liver. This cycle plays a crucial role in regulating energy supply and maintaining blood glucose levels during intense exercise or periods of low oxygen availability, making it vital for metabolic regulation and alternative energy pathways.

5 Must Know Facts For Your Next Test

1. The Cori Cycle helps to recycle lactate produced in muscles back to glucose, which can then be used as an energy source, thus preventing lactate buildup and associated fatigue.
2. During intense exercise, when oxygen levels are low, muscles produce lactate, which is transported to the liver via the bloodstream for conversion back to glucose.
3. This cycle is particularly important in maintaining blood glucose levels during prolonged physical activity or starvation when glycogen stores may be depleted.
4. The Cori Cycle illustrates a critical interplay between muscle and liver metabolism, demonstrating how different tissues collaborate to manage energy resources effectively.
5. Key enzymes involved in the Cori Cycle include lactate dehydrogenase in muscles for lactate production and glucose-6-phosphatase in the liver for converting glucose-6-phosphate back into glucose.

Review Questions

• How does the Cori Cycle contribute to energy production during anaerobic exercise?
  • The Cori Cycle facilitates energy production by recycling lactate produced in muscles during anaerobic conditions back into glucose in the liver. When muscles perform at high intensity and oxygen supply is limited, they convert glucose to lactate for quick energy. This lactate travels to the liver where it's converted back to glucose, which can then be sent back to the muscles or released into the bloodstream to maintain energy supply.
• Evaluate the significance of the Cori Cycle in metabolic regulation and blood glucose homeostasis.
  • The Cori Cycle plays a vital role in metabolic regulation by ensuring that lactate produced during anaerobic glycolysis does not accumulate excessively in muscles. By converting lactate back into glucose, it helps maintain blood glucose levels, especially during times of physical stress or fasting. This process not only supports continuous energy supply but also showcases how different tissues communicate and cooperate to uphold overall homeostasis within the body.
• Synthesize information about how the Cori Cycle interacts with other metabolic pathways during periods of high-intensity exercise and fasting.
  • During high-intensity exercise, the Cori Cycle interacts with pathways such as glycolysis and gluconeogenesis. While muscles utilize anaerobic glycolysis for rapid ATP production, they generate lactate that is shuttled to the liver. There, gluconeogenesis converts this lactate back into glucose for release into circulation. This synthesis process ensures that energy remains available for prolonged activity. Additionally, during fasting, this cycle becomes even more critical as it helps maintain blood sugar levels by utilizing non-carbohydrate sources like lactate while coordinating with glycogenesis to store excess glucose as glycogen.

Related terms

Lactate: A byproduct of anaerobic metabolism, lactate is produced when glucose is broken down for energy without sufficient oxygen, often accumulating in muscles during intense exercise.

Glycogenesis: The biochemical process of converting glucose into glycogen for storage, primarily in the liver and muscle tissues, which can be broken down when energy is needed.

Gluconeogenesis: A metabolic pathway that results in the generation of glucose from non-carbohydrate substrates, crucial for maintaining blood sugar levels during fasting or strenuous exercise.