Glycogen

Question 1

Two functions of debranching enzyme

Answer 1

Transferase and alpha 1,6-glucosidase

Question 2

What three things increase phosphorylation of glycogen phosphorylase?

Answer 2

PKA, DAG/IP3, and Ca2+

Question 3

What form of glycogen phosphorylase is active?

Answer 3

The phosphorylated form

Question 4

What is the function of phosphoprotein phosphatase in the glycogen pathway?

Answer 4

Removes the phosphate from glycogen phosphorylase, inactivating it

Question 5

What does glycogen phosphorylase do?

Answer 5

Breaks down glycogen into glucose 1 phosphate

Question 6

What does AMP do in the glycogen pathway?

Answer 6

Allosterically activates the inactivated form of glycogen phosphorylase

Question 7

How does calcium activate glycogen phosphorylase?

Answer 7

It binds to calmodulin, a subunit of the enzyme

Question 8

What form of glycogen synthase is active?

Answer 8

The unphosphorylated form

Question 9

What can allosterically activate glycogen synthase?

Answer 9

Glucose 6-phosphate

Question 10

What two things in glycolysis does glucagon inhibit?

Answer 10

Pyruvate kinase directly and PFK-1 through inhibition of PFK-2 (inhibition of these promotes gluconeogenesis)

Question 11

What in glycogen pathway does glucagon inhibit?

Answer 11

Glycogenesis by inhibition of glycogen synthase