A andB Indicate which of the conditions listed in the right

Indicate which of the conditions listed in the right column increase the activity of the glycolysis or gluconeogenesis pathways. Glycolysis Gluconeogenesis Increase in ATP Increase in AMP Increase in F-2, 6-BP Increase in acetyl CoA Increase in insulin Increase in glucagon Starvation Fed state

Solution

a) Glycolysis: Increase in F2,6BP; Fed state

Explanation: Glycolysis is the metabolic pathway converting glucose to pyruvate. Thus, glycolysis takes place readily if the levels of glucose are high. Fructose-2,6-bisphosphate (F2,6BP) is a metabolite produced during glycolysis and acts to allosterically modulate the activity of the enzymes phosphofructokinase 1 and fructose 1,6-bisphosphatase, thereby regulating glycolysis. It strongly activates glycolysis through allosteric modulation of phosphofructokinase. Gycolytic enzyme Fructose 1,6-bisphosphatase is inhibited by AMP. ATPs are generated in the gycolytic process. Presence of excess of ATP, inhibits glycolysis.

b) Gluconeogenesis: Starvation and increase in glucagon

Explanation: Gluconeogenesis is the process of synthesis of glucose. Insulin and glucagon are the hormones which balance the blood sugar levels. Glucagon counterbalances insulin. when glucose levels in the body decrease, the pancreas secrete glucagon. Glucagon inturn triggers the liver and muscle cells to change the stored glycogen back into glucose. The process of gluconeogenesis is increased during fasting, starvation, low-carbohydrate diets, or intense exercise.