Glycogenolysis (Food glycogen/starch catabolism)

Question 1

The process of glycogen/starch catabolism

Answer 1

1. O-glycosidic (α1->4) bonds are hydrolysed by the α-amylase from the saliva and pancreas (digestive fluids).
2. Hydrolysis of intra-chains (α1->4) bonds results in the formation of maltose and α-dextrin

Question 2

Maltose

Answer 2

two molecules of glucose linked by an o-glycosidic (α1->4) bond

Question 3

α-dextrin

Answer 3

mixtures of polymers of D-glucose units linked by (α1->4) and (α1->6) glycosidic bonds

**α-dextrin must contains at least 6 units of glucose with (α1->4) bonds and one (α1->6).

Question 4

Steps of glycogen breakdown/catabolism to α-dextrin

Answer 4

Question 5

Last steps of glycogen breakdow/catabolism after α-dextrin is formed

Answer 5

1. α-dextrin is further hydrolysed by α-dextrinase which cleaves (α1->6) bonds.
   R2. emoval of the branching point will be followed by another round of α-amylase digestion.
2. All the Maltose from the repeated breakdown is then hydrolysed by maltase
3. The final product is glucose, which then enters the blood stream

Question 6

Last steps of glycogen breakdow/catabolism after α-dextrin is formed

Answer 6

1. α-dextrin is further hydrolysed by α-dextrinase which cleaves (α1->6) bonds.
   R2. emoval of the branching point will be followed by another round of α-amylase digestion.
2. All the Maltose from the repeated breakdown is then hydrolysed by maltase
3. The final product is glucose, which then enters the blood stream