15: Glucose, Glycogen, and Their Metabolic Regulation
- Page ID
- 68894
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- 15.1: Insulin Signaling in the Liver
- In this section, we will discuss insulin signaling and glycogen synthesis.
- 15.2: Glycogenesis
- The process of forming glycogen is called glycogenesis and it requires the activity of six enzymes. Some of these, we have already discussed including the hexokinase that phosphorylates the 6'-OH of glucose and phosphoglucomutase that converts glucose-6-phosphate to the glucose-1-phosphate isomer. In this section, we will discuss the remaining four enzymes and their role in glycogen biosynthesis. They are Glycogen Synthase, UDP-Glucose Pyrophosphorylase, Glycogenin, & Glycogen Branching Enzyme.
- 15.3: Glycogenolyis and its Regulation by Glucagon and Epinephrine Signaling
- In the previous section, you learned that glucagon signaling down regulates glycogen synthesis. Now lets look at glycogen breakdown, called glycogenolysis and its control by two hormones, glucagon and epinephrine. Only two enzymes are required for the breakdown of glycogen, the glycogen phosphorylase enzyme, and the glycogen debranching enzyme.
- 15.4: Regulation of Glycolysis
- There are three major enzymatic control points within the glycolytic pathway: the hexokinase, the phosphofructokinase, and the pyruvate kinase transitions. Key drivers for regulating the pathway are energy demand within the cell as determined by local indicators such as ATP and AMP, as well as energy demand within the organism as a whole, which can be influenced by hormone signaling pathways. We will also see that the regulation of the pathway can vary depending on cell type and cellular needs.
- 15.5: Regulation of Gluconeogenesis
- There are three major enzymatic control points within the glycolytic pathway: the hexokinase, the phosphofructokinase, and the pyruvate kinase transitions. Key drivers for regulating the pathway are energy demand within the cell as determined by local indicators such as ATP and AMP, as well as energy demand within the organism as a whole, which can be influenced by hormone signaling pathways. We will also see that the regulation of the pathway can vary depending on cell type and cellular needs.