Endocrine Module PDF

Endocrine Module **Key Terms Related to Glucose and Glycogen** 1. **Glycolysis** - **Breakdown of glucose** to produce energy. - Think: Glucose → Energy (used by cells). - Happens in: **Muscles and most cells**. 2. **Glycogenesis** - **Making glycogen** from glucose...

Endocrine Module **Key Terms Related to Glucose and Glycogen** 1. **Glycolysis** - **Breakdown of glucose** to produce energy. - Think: Glucose → Energy (used by cells). - Happens in: **Muscles and most cells**. 2. **Glycogenesis** - **Making glycogen** from glucose for storage. - Think: Glucose → Glycogen (stored in liver and muscles). - Happens: **After eating**, when glucose is high. 3. **Glycogenolysis** - **Breaking down glycogen** into glucose to release energy. - Think: Glycogen → Glucose (for use). - Happens: During **fasting** or **exercise**. 4. **Gluconeogenesis** - **Making new glucose** from non-carbohydrate sources (like amino acids, glycerol, or lactate). - Think: \"New glucose\" when you're low on it. - Happens: **In the liver** during **fasting** or **starvation**. **More terminology** - **Hepatocytes**: - **Liver cells**. - They help with **storing glycogen**, **producing glucose** (gluconeogenesis), and **detoxifying** substances. - **Myocytes**: - **Muscle cells**. - They store **glycogen** and use it to produce **energy** during movement or exercise. - **Adipocytes** - **Fat cells**. - They store **fat (lipids)** for energy. - They also help regulate **energy balance** and **hormones**, playing a role in metabolism. A screenshot of a medical information Description automatically generated with medium confidence  **GLUCAGON IS RELEASED FROM A-CELLS OF THE PANCREAS. GLUCAGON SIGNALS THE LIVER TO RELEASE GLUCOSE.** **GLUCOSE IS STORED IN THE LIVER AS GLYCOGEN.** **INSULIN IS RELEASED FROM THE B-CELLS OF THE PANCREAS.** **INSULIN ACTS ON THE LIVER, IT IS THE TARGET ORGAN.**   A close-up of a medical information Description automatically generated  A close-up of a document Description automatically generated  **MEMORISE THIS**  **HEPATOCYTES = CELLS OF THE LIVER**   **WE ARE FOCUSSING ON 5!!.**  A diagram of a cell membrane Description automatically generated  A diagram of a human body Description automatically generated  = **a molecule moves from a high concentration to a low concentration.** This occurs during passive transport and does not require energy.  **1. Insulin Stimulates Glucokinase Expression** - **What does glucokinase do?** - It converts **glucose** into **glucose-6-phosphate (G6P)** inside liver cells. - This step is crucial because G6P **traps glucose** in the cell, preventing it from leaving. - **Why does insulin stimulate glucokinase?** - By activating glucokinase, insulin ensures that the liver can efficiently take in glucose from the bloodstream and **store or use it**. **2. Insulin Stimulates Glycogen Synthase Activity** - **What does glycogen synthase do?** - It **builds glycogen** from glucose molecules for storage in the liver and muscles. - **Why does insulin activate glycogen synthase?** - After a meal, insulin tells the body to **store excess glucose** as glycogen, creating a reserve to be used later when glucose is needed (e.g.during fasting). **3. Insulin Inhibits Glycogen Phosphorylase** - **What does glycogen phosphorylase do?** - It **breaks down glycogen** into glucose, releasing it into the bloodstream. - **Why does insulin inhibit glycogen phosphorylase?** - When glucose levels are high, the body doesn\'t need more glucose in the blood. Insulin stops glycogen breakdown to **keep glucose levels stable**. **4. Insulin Inhibits Glucose-6-Phosphatase** - **What does glucose-6-phosphatase do?** - It **converts glucose-6-phosphate (G6P) back into free glucose**, allowing it to leave the liver and enter the bloodstream. - **Why does insulin inhibit glucose-6-phosphatase?** - If insulin didn't block this enzyme, the liver would keep releasing glucose, which would **raise blood glucose levels unnecessarily** after a meal. **HEPATOCYTES = LIVER CELLS**  **MYOCYTES = MUSCLE CELLS** **ADIPOCYTES = FAT CELLS**  A screenshot of a cell phone Description automatically generated **Lipogenesis = the formation of fats (lipids)**  A close-up of a white paper Description automatically generated   A white background with black text Description automatically generated  A graph of glucose and glucagon Description automatically generated   A screenshot of a medical report Description automatically generated