Glycogen: Metabolism and Disorders

Question 1

What is Glycogen

Answer 1

A polymer made from glucose which serves as a form of Energy Store.

Question 2

The 2 pathways to mantain blood glucose levels during fasting

Answer 2

Glycogenolysis and Gluconeogenesis

Question 3

Which human cell can use only glucose as source of energy

Answer 3

Erythrocyte

Question 4

Where do Glycogenolysis and Gluconeogenesis happen

Answer 4

Liver and muscle cells

Question 5

What is Glycogenesis

Answer 5

Conversion of glucose molecules into Glycogen

Question 6

Regulation of Glycogenesis

Answer 6

Allosteric via Glycogen Synthase.
Activated = insulin and cortisol
Inhibited = glucagon and epinephrine.

Question 7

What is Glycogenolysis

Answer 7

Conversion of Glycogen into glucose molecules

Question 8

Regulation of Glycogenolysis

Answer 8

Allosteric via Glycogen Phosphorylase.
Activated = glucagon, epinephrine or AMP
Inhibited = insulin, ATP, glucose-6-phosphate

Question 9

Insulin is implicated in _________ reactions

Answer 9

Anabolic

Question 10

Glucagon is implicated in ___________ reactions

Answer 10

Catabolic

Question 11

Fed state increases ________ concentration

Answer 11

Insulin

Question 12

Fasting state increases ____________ concentration

Answer 12

Glucagon

Question 13

Insulin promotes which metabolic reactions

Answer 13

Glycolysis
Glycogenesis
Fatty acid synthesis
Protein synthesis

Question 14

Glucagon promotes which metabolic reactions

Answer 14

Glycogenolysis
Gluconeogenesis

Question 15

Glucagon type of signal pathway

Answer 15

G-Protein coupled Receptor

Question 16

First step after Activation of Protein Kinase by glucagon

Answer 16

Activation of Glycogen Phosphorylase

Question 17

Insulin type of signal pathway

Answer 17

Tyrosine-Kinase receptor

Question 18

Activation of Protein Phospathase-1 by insulin leads to

Answer 18

Activation of Glycogen synthase

Question 19

What does the tyrosine-kinase receptor do when stimulated by Insulin

Answer 19

Activation of Protein Phosphatase = Activation of Glycogen Synthase

Question 20

Von Gierke disease is cause by deficiency of

Answer 20

Glucose-6-phosphatase (LAST STEP in Glycogenolysis)

Question 21

Which molecule is accumulated in Von Gierke Disease

Answer 21

Glucose-6-phosphate

Question 22

Von Gierke disease features

Answer 22

Clinic: Severe fasting hypoglycemia + Doll-like faces + Hepatomegaly
Lab: Elevated lactate and uric acid

Question 23

Pompe disease is cause by deficiency of

Answer 23

Lysosomal alpha 1,4 glucosidase

Question 24

Pompe disease features

Answer 24

Cardiomegaly + Exercise intolerance + Weakness

Question 25

Cori disease is caused by deficiency of

Answer 25

Debranching enzyme

Question 26

Cori disease special feature

Answer 26

Fasitng Hypoglycemia with NORMAL LACTATE levels

Question 27

McArdle disease is caused by deficiency of

Answer 27

MUSCLE Glycogen Phosphorylase

Question 28

McArdle disease features

Answer 28

Muscle pain w/ exercise + Myoglobinuria + 2ND WIND EFFECT

Question 29

What is the final product of HMP Shunt

Answer 29

1 RIBOSE
1 CO2
2 NADPH

Question 30

What reactant does HMP Shunt use

Answer 30

Glucose-6phospate

Question 31

Where does HMP Shunt occur

Answer 31

Cytosole

Question 32

Regulation of HMP Shunt

Answer 32

Allosteric via G-6PD

Question 33

What is G-6PD Deficiency’s inheritance pattern

Answer 33

X-Linked Recessive

Question 34

What is G-6PD pathophysiology

Answer 34

Deficiency of G-6PD produces a decreases in Reduced Glutathione leading to Oxidative damage

Question 35

G-6PD clinical features

Answer 35

Hemolytic anemia in crisis triggered by stressors like Fava Beans, Sulfonamides and infections