Question

Fast State: explain in brain the changes in metabolism pathway ( CHO, Portions, Fats) with their enzymes

Answer 1

Ans:

• The Fast state is also known as postabsorptive state. It occurs when the food has been digested, absorbed and stored.
• During this state, the body relys intially on stored glycogen.In response, the glucose levels decreases in blood resulting in insulin levels to drop.
• Falling glucose levels trigger the pancreas(alpha cells) to release glucagon which inhibits the glycogen synthesis in the liver and stimulates the breakdown of stored glycogen back into glucose. This is used by the peripheral tissues and brain.
• If glycogen stores are depleted during fasting, fatty acids and proteins can be metabolized and used as fuel.
• Fatty acids can be converted into acetyl CoA and processed through Krebs cycle to make ATP.
• Glucogenesis also begins in the liver by liberating glycerol from fattyacids to replace the glucose and is used by brain and organs.
• If fast is continued, ketone bodies are created from fats and serve as the fuel source for the heart and other organs, so that the brain can still use glucose.
• Once these stores are depleted, proteins will be used as alternatives.Proteins are released from muscle cells and broken down for glucose synthesis.