Carb Metabolism

Question 1

What are the 4 main roles Glucose plays?

Answer 1

1- Source of ATP
2-Energy storage as Glycogen
3-Molecular precursor for AA and neurotransmitters
4-Structural backbone

Question 2

What are the 4 catabolic pathways of glucose?

Answer 2

1-Glycolysis
2-Citric acid cycle
3-Oxidative phosphorylation
4-Glycogenolysis

Question 3

What are the two Anabolic Pathways for Glucose?

Answer 3

1-Gluconeogenesis (makes glucose)

2-Glycogenesis (Make Glycogen)

Question 4

What 4 enzymes help break down sugars?

Answer 4

1-Amylase
2-Lactase
3-Sucrase
4-Maltase

Question 5

What are the 5 key regulators of Glucose metabolic pathways?

Answer 5

1-Insulin
2-Glucagon
3-Epinephrine
4-Glucose
5-ATP/AMP concentrations

Question 6

When Glycolysis is happening, which pathway is not?

Answer 6

Gluconeogensis

Question 7

When Glycogensis is happening, which pathway is not?

Answer 7

Glycogenolysis

Question 8

What two places/areas is glycogen primarily found?

Answer 8

Liver (10% weight) Muslces (2% weight)

Question 9

What does Glycogenesis do?

Answer 9

Convert Glucose to Glycogen

Question 10

What enzyme is the point of regulation of Glycogenesis?

Answer 10

Glycogen Synthase (Converts Uracil diphosphate Glucose to Glycogen Chain)

Question 11

What enzyme phosphorylates Glucose to make Glucose-6-phosphate?

Answer 11

Hexokinase

Question 12

What enzyme converts Glucose 6 phosphate to Glucose 1 phosphate?

Answer 12

Phosphoglucomutase

Question 13

Which Enzyme converts Glucose 1 phosphate to Uracil Diphosphatate-Glucose?

Answer 13

UDP-Glucose pyrophosphorylase

Question 14

What protein acts as a tethering point for Glycogen formation?

Answer 14

Glycogenin

Question 15

What does Glycogenolysis do?

Answer 15

Create Glucose from Glycogen

Question 16

What does Glucose-6 Phosphatase do? Where is it found?

Answer 16

Dephosphorylates G6P to Glucose. Only found in the ER. Glucose is then transported into the blood stream

Question 17

What two enzymes regulate glycogen metabolism?

Answer 17

Glycogen Synthase, Glycogen Phosphorylase

Question 18

What does Glycogen synthase do?

Answer 18

Add UDP-Glucose to Glycogen chains

Question 19

What does Glycogen Phosphorylase do?

Answer 19

Remove Glucose 1 phosphate from Glycogen

Question 20

How is Glycogen synthase regulated?

Answer 20

• Inactivated by GSK3 through phosphorylation (3 phosphates)

- Activated when PP1 dephosphorylates it

Question 21

What three things favor the activation of Glycogen Synthase?

Answer 21

Insulin, Glucose 6 Phosphate, Glucose

Question 22

What do Epinephrine and Glucagon do?

Answer 22

Raise blood/cellular glucose level. Epinephrine in most of the body. Glucagon acts in the liver

Question 23

What two things inhibit Glycogen Phosphorylase?

Answer 23

Glucose and Insulin

Question 24

What does gluconeogensis do?

Answer 24

Make Glucose

Question 25

What is the cost to make Glucose?

Answer 25

4 ATP 2 GTP 2 NADH + H

Question 26

What is the point of regulation in gluconeogenesis?

Answer 26

Fructose 1,6 bisphosphatase 1 dephosphorylating F 1,6 BP to Fructose 6 Phosphate

Question 27

What can be converted to glucose when you have surpassed your aerobic ability?

Answer 27

Lactate

Question 28

What is driven by Pyruvate Conversion to PEP?

Answer 28

Gluconeogensis

Question 29

Pyruvate carboxylase converts bicarbonate and Pyruvate to what?

Answer 29

Oxaloacetate

Question 30

What is Oxaloacetate converted into?

Answer 30

Phosphoenolpyruvate

Question 31

How many pyruvate are required to eventually make 1 glucose?

Answer 31

2

Question 32

What 4 things regulate gluconeogenesis?

Answer 32

PFK-1 FBPase-1 Insulin Acetyl CoA

Question 33

How does PFK-1 regulate Gluconeogenesis?

Answer 33

down regulates by converting F6P to F1,6P to drive glycolysis

Question 34

How does FBPase regulate Gluconeogenesis?

Answer 34

Dephosphorylates F1,6P to convert it to F6P and drive Gluconeogenesis

Question 35

How does Insulin regulate Gluconeogenesis?

Answer 35

down regulates it by de-activating fox transcription factor (inhibiting transcription of PEP Carboxylase and Glucose 6 phosphatase)

Question 36

How does Acetyl-CoA regulate Gluconeogenesis?

Answer 36

acts in a feedback loop to: - inhibit conversion of pyruvate to acetyl CoA - Up regulate conversion of oxaloacetate

Question 37

Levels of what help regulate intracellular metabolic function?

Answer 37

ATP/AMP levels (Detected by AMPK)

Question 38

What happens in a Feeding (insulin) state?

Answer 38

increase glucose uptake, store extra as glycogen

Question 39

What happens in a fasting (glucagon) state?

Answer 39

increase glucose release by breaking down glycogen