Glycogenesis

Question 1

Branching of Glycogen?

Answer 1

Highly branched chain.

Question 2

What types of glycosidic bonds are there?

Answer 2

ALPHA 1-4

ALPHA 1-6

Question 3

Where are ALPHA 1-4 bonds found?

Answer 3

Within chains.

Question 4

Where are ALPHA 1-6 bonds found?

Answer 4

Branch points.

Question 5

When is glycogenesis activated?

Answer 5

After a carbohydrate rich meal.

Question 6

What happens to glucose after a meal?

Answer 6

The glucose enters hepatocytes freely.

Question 7

What allows Glucose to enter hepatocytes?

Answer 7

Glut2 receptor.

Question 8

What does insulin do for Glycogenesis?

Answer 8

Stimulates it.

Question 9

What happens to Glucose in hepatocytes?

Answer 9

Glucose –> G-6-P (Glucokinase)

Question 10

What happens to G-6-P?

Answer 10

G-6-P –> G-1-P (Phosphoglucomutase)

Question 11

What happens to G-1-P?

Answer 11

G-1-P –> UDP Glucose (UDP-Glucose Pyrophosphorylase)

Question 12

What does the UDP-G do?

Answer 12

Binds onto the protein Glycogenin.

Question 13

How is the glycogen chain elongated?

Answer 13

UDP Glucose is added at the non-reducing end.

Question 14

What enzyme elongates the glycogen chain?

Answer 14

Glycogen Synthase.

Question 15

What bonds are formed when the chain increases in length?

Answer 15

APLHA 1-4 bonds.

Question 16

What enzyme branches the glycogen?

Answer 16

Glycogen branching enzyme.

Question 17

What bonds are formed during branches?

Answer 17

ALPHA 1-6.

Question 18

Why is glycogen branched?

Answer 18

Makes the glycogen more soluble, so can store far more as glycogen than glucose.
increases number of non-reducing ends so glycogen synthase and glycogen phosphorylase can act on more ends.

Question 19

When is Glycogen Synthase less active?

Answer 19

When Phosphorylated.