Glycogen synthesis

Question 1

Where can carbohydrates be stored?

Answer 1

Can be stored as glycogen in the liver and muscles

Question 2

What happens to excess carbohydrates when glycogen reserves are full?

Answer 2

full excess carbohydrate is converted to fat for storage.

Question 3

What is Surplus glucose stored as?

Answer 3

It is stored as glycogen

Question 4

How does Glycogenesis begin?

Answer 4

Begins with the the phosphorylation of glucose by glucokinase and by hexokinase .

Question 5

How do we activate our glucose molecule

Answer 5

1. Glucose is phosphorylated by glucokinase and by hexokinase (this costs 1ATP)
2. Then glucose-6-phosphate is converted into glucose-1-phosphate by phosphoglucomutase
3. glucose-1- phosphate is converted to uridine diphosphate (UDP) glucose catalysed by UDP glucose pyrophosphorylase

Question 6

What do glucokinase and hexokinase do?

Answer 6

Phosphorylates glucose into Glucose 6-phosphate (this requires 1ATP)

Question 7

What does phosphoglucomutase do?

Answer 7

Converts Glucose 6-phosphate into Glucose 1-phosphate

Question 8

What does UDP- Glucose

pyrophosphorylase do?

Answer 8

Converts Glucose 1-phosphate into UDP glucose

Question 9

Why does glucose need to be activated before glycogen synthesis can begin?

Answer 9

Glucose needs to be activated before it can be added to the no reducing end of the glycogen chain

Question 10

How may ATPs does it take to activate glucose?

Answer 10

1

Question 11

What drives the activation of glucose reaction?

Answer 11

The formation of UDP and pyrophosphate

These pyrophosphate can be phosphorylated to release 2 free energy inorganic phosphates

Question 12

After guise has been activated what does it need to do?

Answer 12

It needs to be coupled onto our glycogen

Question 13

What do we need to be able to couple our activated glucose onto glycogen?

Answer 13

A primer

Question 14

Name the primer we use to couple our activated glucose onto glycogen?

Answer 14

It is glycogen with a minimum number of sub units

Question 15

How is our initial glycogen formed by?

Answer 15

By glycogenin

Question 16

Name theentyme that joins glycogen and the active form of glucose

Answer 16

Glycogen synthase

Question 17

Name the only link glycogen synthase can produce

Answer 17

Glycogen 1,4 linkage

Question 18

Name a common intermediate found in carbohydrate condensation reactions

Answer 18

Nucleoside diphosphate

Question 19

What provides the energy needed to link the active glucose to the non reducing end on glycogen ?

Answer 19

The high energy bond between
the sugar and the nucleoside diphosphate
provides the energy needed to link the new
sugar to the non reducing end.

Question 20

How is the branching of the glycogen completed?

Answer 20

It is completed by transferring a minimum of 6 alpha (1-4) glucan units from the elongated chain onto the sam for neighbouring chain by introducing an alpha (1-6^) linkage

Question 21

Name the enzyme that helps for branches on glycogen

Answer 21

The branching enzyme

Question 22

How Does the branching enzyme work?

Answer 22

Works by taking a block of units from the non reducing terminal of a glycogen polymer
It breaks an alpha 1-4 linkage and for an alpha 1-6 linkage

Question 23

What conditions need to be fulfilled so that the branching enzyme can work?

Answer 23

1. You need a minimum chain length of 10-11 sub units

2. Branching enzymes needs to attach at least 4 units into the glycogen chain

Question 24

What is Andersons disease caused by?

Answer 24

A deficiency in the branching enzyme

Question 25

What are the consequences of having Andersons disease

Answer 25

Liver failure and death in the first year of life

Question 26

Talk through the hormonal control of glycogen synthesis

Answer 26

1. Insulin receptor (Tyrosine kinase) activated protein kinase 2. Protein kinase activates Phosphoprotein phosphatase 1 3. Phosphoprotein phosphatase 1 does 2 things: A. Inhibits glycogen phosphorylase b thus switching go glycogen breakdown B. Activantes glycogen synthase a so that glycogen synthase occurs

Question 27

Where is insulin secreted from?

Answer 27

Secreted from the pancreas

Question 28

When is insulin secreted?

Answer 28

Secreted in response to increased blood glucose

Question 29

After being secreted from the pancreas where does insulin go?

Answer 29

Insulin travels to taget tissues eg muscles, liver and adipose There is binds to the membrane receptors and effects metabolise to promote synthesis of glycogen

Question 30

What does insulin do in the muscle

Answer 30

1 Insulin briefly increases the number of membrane glucose transporters 2. Increases glucose uptake from the blood 3. Also activates glycogen synthesis so the glucose can be stored as glycogen

Question 31

What does insulin do in the liver

Answer 31

1. Takes up glucose fro blood so insulin doesn't influence the number of membrane glucose transporters 2. Insulin activates glycogen synthesis so liver is able to store more glucose as glycogen

Question 32

How much glycogen can we sore in the body?

Answer 32

About 300 g

Question 33

What happens once glycogen stores are full

Answer 33

Glucose entering the liver will be converted into dat and sent to the adipose tissues to be stored

Question 34

What does insulin do in the adipose tissue

Answer 34

1. Insulin briefly increases the number of membrane glucose transporters 2. You get an increased glucose uptake fro te blood 3. Insulin also stimulates the conversion of guise to fat for storage

Question 35

What is diabetes type 1

Answer 35

It is insulin dependent diabetes caused by a deficiency of insulin due to beta cell destruction

Question 36

How I diabetes type 1 treated?

Answer 36

Treated with insulin

Question 37

What is diabetes type II

Answer 37

It is non insulin dependent diabetes | It is a long term disorder that is primarily characterized by insulin resistance

Question 38

Give some risk factors of diabetes II?

Answer 38

Obesity | Genetic factors

Question 39

How is diabetes II treated?

Answer 39

Diet Exercise Hypoglycemic drugs, sometimes insulin.

Question 40

What oral implications are associated with uncontrolled diabetes?

Answer 40

Elvated blood glucose causes salivary glucose concentration to increase This has an impact on oral microbiology leading to increased oral disease especially periodontal disease

Question 41

Name the disease that occurs due to A deficiency in the branching enzyme

Answer 41

Andersons disease