Feeding and fasting with cases

Question 1

1. Describe the effect of insulin or glucagon on key enzymes in glycolysis, gluconeogenesis and glycogen metabolism.

Answer 1

glycolysis- bifunctional enzyme- glucagon inactivates PFK-2, glucagon inactivates PDH complex, glucagon inactivates Pyruvate kinase

gluconeo-

glycogen- glucagon inactivates glycogen synthase, and activates glycogen phosphorylase

Question 2

2. Describe the role of insulin and glucagon on fatty acid synthesis, fatty acid mobilization and ketogenesis.

Answer 2

glucagon down regulate fatty acid synthesis, upregulate beta ox

Question 3

3. Describe the changes in insulin, glucagon, triglycerides, fatty acids and glucose following a meal.

Answer 3

insuin up, glucagon down, truglycerides up, fatyy acids up, glucose up

Question 4

4. Be able to distinguish between glucose metabolism in the liver, RBCs, muscle and brain under fed and fasting conditions.

Answer 4

RBC’s only produce lactate. RBC’s always need glucose, brain can handle ketone bodies, but prefers glucose, same with the muscle