Biochemistry help 1) Discuss the biochemical pathway by which hepatocytes and my

Question

Biochemistry help

1) Discuss the biochemical pathway by which hepatocytes and myocytes synthesize activated form of D-glucose for the biosynthesis of glycogen. (draw out all structures and show how the synthesis takes place)

2) Write the names of the enzymes used by hepatocytes and myocytes to synthesize glycogen. Discuss the role of each enzyme in the biosynthesis of glycogen.

3) Write the names of the enzymes and accessory molecules used by hepatocytes and myocytes to degrade glycogen

4) What is the product of glycogen degradation in hepatocytes and myocytes?

Explanation / Answer

2. a) Excess of glucose is converted into glucose-6-phosphate by the enzyme called glucokinase(hepatocytes) or hexokinase(other cells).

b) Glucose-6-phosphate is turned into glucose-1-phosphate by phosphoglucomutase.

c) This glucose-1-phosphate combine to Uridine triphosphate to form UDP-glucose. This UDP-glucose is added to growing glycogen by the enzyme called glycogen synthase.

1. a) Glycogen is break down by glycogen debranching enzymes.. They are amylo-1,6-glucosidase and 4-alfa-glucanotransferase.

b) Debrancing enzymes remove glucose residues from the branch points (a-1,6 linkage) in glycogen.

c) Glucotransferase removes three glucose residues of one branch.

d) The glucose in a-(1,6)-linkage is removed by glucosidase to release D-glucose in the myocytes (skeletal muscle). This free glucose enter blood stream.

4. In myocytes glycogen breakdown produces glucose-6-phosphate for glycolysis, where are in hepatocytes phosphate is removed from glucose-6-phosphate to from free glucose by enzyme called glucose-6-phosphatase.

Related Questions

Navigate

• Browse (All)
• Browse B
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.