Question

In the indicated tissues, what hormone (and associated glucose levels) will result in the up-regulation or increased activity of the listed processes and/or enzymes:  Glucagon or Insulin? Use “G” for Glucagon, “I” for Insulin or “N” for neither.

Triacylglygerol Lipase (Adipocyte)

Glycogen Phosphorylase (Liver)

Phosphofructokinase-1 (Liver)  

Fructose 2,6 Bisphosphatase (Liver)

Pyruvate Dehydrogenase (Liver)

Glycogen Synthase (Liver)

Acetyl-CoA Carboxylase (Liver)

Hexokinase II (Muscle)

Answer 1

Triacylglygerol Lipase (Adipocyte) - G

Glycogen Phosphorylase (Liver) - G

Phosphofructokinase-1 (Liver) - I

Fructose 2,6 Bisphosphatase (Liver) - I

Pyruvate Dehydrogenase (Liver) - I

Glycogen Synthase (Liver) - G

Acetyl-CoA Carboxylase (Liver) - I

Hexokinase II (Muscle) – I.

Triacylglygerol Lipase (Adipocyte) – G

Glucagon promotes lipolysis by increasing the activity of adipocyte triacylglygerol lipase (ATGL) and hormone-sensitive lipase (HSL).

Glycogen Phosphorylase (Liver) – G

Glucagon promotes glycogen breakdown by upregulating glycogen phosphorylase in the liver.

Phosphofructokinase-1 (Liver) – I

Insulin promotes glycolysis by increasing the activity of phosphofructokinase 1.

Fructose 2,6 Bisphosphatase (Liver) – I

Insulin promotes glycolysis by increasing the activity of fructose-2,6-bisphosphatase (FBPase). F2,6P is an inhibitor of glycolysis. FBPase-2 cleaves it and promotes glycolysis.

Pyruvate Dehydrogenase (Liver) – I

Insulin promotes glucose metabolism by increasing the activity of pyruvate dehydrogenase (conversion of pyruvate to acetyl-CoA).

Glycogen Synthase (Liver) – G

Glucagon promotes glycogenesis by upregulating glycogen synthase.

Acetyl-CoA Carboxylase (Liver) – I

Insulin promotes lipogenesis by upregulating acetyl-CoA carboxylase.

Hexokinase II (Muscle) – I.

Insulin promotes uptake of glucose by cells via upregulating hexokinase II.