glycogen metabolism 2

Question 1

What are the two key enzymes that regulate glycogen metabolism

Answer 1

glycogen synthase- favors glycogenesis

glycogen phosphorylase- favors glycogenolysis

Question 2

describe the active and inactive forms of glycogen synthase

Answer 2

active- a form-non phosphorylated a form

inactive- b form- phosphorylated

Question 3

what is the most important enzyme that phosphorylases glycogen synthase what controls it

Answer 3

glycogen synthase kinase

Question 4

what molecule is an alloosteric regulator of glycogen synthase

Answer 4

G-6-P

Question 5

What are the two major forms of glycogen phosphorylase and where is each one found

Answer 5

Active “a” form (R relaxed state) – in liver- phosphorylated

Inactive “b” form (T tense state) – in muscle- non phosphorylated

Question 6

mutation in Live GP causes ?

mutation in muscle GP causes

Answer 6

Mutation in liver GP causes Hers disease

Mutation in muscle GP causes McArdle syndrome

Question 7

What affect does glucose have on phosphorylase a

Answer 7

changes it to the Tense state

Question 8

what affect does AMP/ATP have on phosphorylase B

Answer 8

activated by AMP goes to Relaxed state

ATP and G-6-P cause to go to tenses state

Question 9

When is glycogenesis favored

Answer 9

Glycogenesis favored in fed state
– blood glucose high
– insulin high
– cellular ATP high

Question 10

when is glycogenolysis favored

Answer 10

• Glycogenolysis favored in fasting state
– blood glucose low
– glucagon high
• Glycogenolysis also favored during exercise
– cellular calcium high (in exercising muscles)
– AMP high (from breakdown of ATP)

Question 11

disease: 1 von glerke
defective enzyme
organ affected
glycogen in affected organ

Answer 11

defective enzyme-G-6-phosphotase
organ affected- liver and kidney
glycogen in affected organ- glycogen amount increased