Basic Glycogen Met

Question 1

What important feature is there due to both breakdown and synthesis of glycogen occurring?

Answer 1

Reciprocal Regulation

Question 2

How many reactions are involved in the synthesis of glycogen from Glucose-1-Phosphate?

Answer 2

2

Question 3

Are the reactions involved in the synthesis of glycogen from glucose-1phosphate reversible or irreversible?

Answer 3

Irreverisble

Question 4

What are the intermediates in the synthesis of glycogen from glucose-1-phosphate?

Answer 4

UDP-glucose and PPi

Question 5

What is combined with glucose-1-phosphate in the initial step of glycogen synthesis?

Answer 5

UTP

Question 6

What enzyme is used in the initial step of glycogen synthesis?

Answer 6

UDP-glucose phosphorylase

Question 7

What enzyme is involved in the conversion of UDP-glucose + PPi to Glycogen?

Answer 7

glycogen synthase

Question 8

Which enzyme involved in glycogen synthesis is involved in regulation of the process?

Answer 8

glycogen synthase

Question 9

What is the first step involved in the breakdown of glycogen? Is it reversible or irreversible?

Answer 9

Glycogen + Pi to glucose-1-phosphate

Reversible

Question 10

What enzyme is involved int he first stepof breakdown of glycogen?

Answer 10

glycogen phosphorylase

Question 11

What is the significance in the difference between the first step in glycogen breakdown and the last steps of glycogen synthesis?

Answer 11

They mirror each other
But synthesis bypasses the reversible reaction seen in breakdown by using irreversible reactions and going via the UDP-glucose intermediate from glucose-1-phosphate

Question 12

What is the second reaction involved in the breakdown of glycogen? Reversible or irreversible? Enzyme?

Answer 12

glucose-1-phosphate to glucose-6-phosphate
reversible
via phosphoglucomutase

Question 13

What 3 key processes does glucose-6-phosphate go on to in the breakdown of glycogen?

Answer 13

Pentose phosphate pathway as Ribose + NADPH
Maintain blood (or other tissue) glucose levels
Glycolysis (muscle/brain)

Question 14

What enzyme is used in the conversion of glucose-6-phosphate for use in the pentose phosphate pathway and where does this occur?

Answer 14

glucose-6-phosphatase

only in the liver

Question 15

What small molecule is used in the conversion of glucose-6-phosphate to Glucose to maintain blood glucose levels?

Answer 15

water (H2O)