Carb Metabolism 4

Question 1

Where does glycogen synthesis occur?

Answer 1

liver and muscle

Question 2

Glucose 6 P —> ? –> gluc 1 p?

Answer 2

phosphoglucomutase

Question 3

glu 1 P –> ? –> UDP glucose?

Answer 3

UDP-glucose pyrophosphorylase

Question 4

Glycogen is synthesized in the cytosol on a primer protein called?

Answer 4

glycogenin

Question 5

What enzymes transfers glucose residues from UDP-glucose to the nonreducing ends of glycogen chains?

Answer 5

glycogen synthase

Question 6

Branching is introduced on glycogen by what enzyme?

Answer 6

branching enzyme

Question 7

When does glycogen degradation occur?

Answer 7

when blood glucose levels are low

Question 8

What enzyme is the first step in glycogen degradation?

Answer 8

glycogen phosphorylase

Question 9

What process involves glycogen phosphorylase, phosphoglucomutase, glucose 6 phosphatase and debranchnig enzymes?

Answer 9

glycogen degradation

Question 10

What process involves hexokinase, phosphoglucomutase , UDP-glucose pyrophosphorylase, glycogen synthase, and branchign enzymes?

Answer 10

glycogen synthesis

Question 11

During glycogen degradation, what is released from debranched chains of a 1,4 linked glucoses?

Answer 11

glucose phosphates

Question 12

Glucokinase is NOT inhibited by what product?

Answer 12

gluc 6 phosphate

Question 13

Glycogen synthase is stimulated by what? Inhibited by what?

Answer 13

+ insulin

- glucagon, epinephrine

Question 14

Insulin ____ blood sugar concentration.
Glucagon _____ blood sugar concentration.
Epinephrine ____ ATP production from glycogen and glucose.

Answer 14

lowers
raises
stimulates

Question 15

Can muscles respond to glucagon? Why or why not?

Answer 15

NO!!!! they cannot release glucose as they are lacking glucose 6 phosphatases

Question 16

In response to epinephrine, what happens in the liver and muscle?

Answer 16

stimulates breakdown of glycogen in the liver

activate glycolysis in the muscle to make ATP

Question 17

Phosphorylation favors glycogen ______?

Answer 17

degradation

Question 18

In their phosphorylated states, glycogen phosphorylase is what and glycogen synthase is what?

Answer 18

glycogen phosphorylase –> active

glycogen synthase –> inactive

Question 19

Steps of glucagon binding in the liver in response to low levels of glucose.

Answer 19

1. glucagon and epinephrine bind to cell surface receptors.
2. adenylate cyclase activated
3. increased cAMP –> activates PKA
4. PKA activates phosphorylase kinase by phosphorylation
5. phophorylase kinase phosphorylates glycogen phosphorylase

Question 20

In response to insulin, insulin binds to what type of receptor on the cell to initiate it’s response?

Answer 20

protein phosphatase 1 (PP1)

Question 21

What does PP1 do?

Answer 21

activates glycogen synthase and inactives glycogen phosphorylase

Question 22

Insulin causes what 4 effects in the liver?

Answer 22

activates glycogen synthase
inactiviates glycogen phosphorylase
stimulates glycolysis and ATP generation
no effect on glucose update

Question 23

Glucagon causes what 4 things in the liver?

Answer 23

activates, glycogen phosphorylase, glucose 6 phosphatase, and glycogeneogenesis

inhibits glycogen synthase

Question 24

Epinephrine causes what 4 things in the liver?

Answer 24

activates glycogen phosphorylase and glucose 6 phosphate

inactivates glycaon synthase

does NOT STIMULATE GLYCOLYSIS

Question 25

Insulin effects in the muscle? 3 thigns

Answer 25

stimulates glucose uptake, stimulates glycolysis and ATP, increase muscle glycogen and creatine phosphate levels

Question 26

Effects of glucagon on muscle?

Answer 26

NONE

Question 27

Effects of Epinephrine on the muscle?

Answer 27

activates glycogen phosphorylase and inactivates glycogen synthase

stimulates glycolysis

Question 28

Before breakfast, what is the main source of blood glucose?

Answer 28

gluconeogensis

Question 29

Wha is van Gierke disease?

Answer 29

defect in gluocse 6 phosphatase; liver and kidney cannot export glucose and leads to hypoglycemia and increased liver glycogen stores

Question 30

Type 1 glycogen storage disease name?

Answer 30

van Gierke

Question 31

Van Gierke is what # glycogen storage disease? WHy?

Answer 31

Type 1; defect in glucose 6 phosphatase

Question 32

What is Pompe Disease?

Answer 32

deficiency in acid maltase (or a-glucosidease); accumulation of glycogen in the lysosomes over time

Question 33

What is Type II glycogen storage disease?

Answer 33

Pompe

Question 34

What is Cori Disease?

Answer 34

Type III, disease in glycogen debranching enzyme

Question 35

What is Type 5 glycogen disorder disease?

Answer 35

McArdle; defect in muscle glycogen phosphorylase; unable to break down glycogen; muscle cramps during exercise

Question 36

What disease presents with muscle cramps during periods of high glucose demands?

Answer 36

McArdle’s; Type 5

Question 37

What are the 2 mechanisms in which alcohol metabolism occurs?

Answer 37

1. Alcohol dehydrogenase and Aldehydge Dehydrogenase

2. p450 system (MEOS)

Question 38

What is one bad thing about the MEOS system?

Answer 38

oxidize NADPH; do you wont have as much

Question 39

Ethanol metabolism reduces the amount of what and increases the amount of what in the cytoplasm?

Answer 39

decrease NAD and increases NADH

Question 40

What 2 mechanisms are affected when NADH is high?

Answer 40

pyruvate and OAA will get converted quickly by Lactate DH and malate DH –> lactate and malate

Question 41

Ethanol metabolism in the liver generates NADH, which reduces the capacity for what and blocks what?

Answer 41

reduces the capacity for gluconeogeneis

and blocks CAC