Gluconeogenesis

Question 1

What hormone stimulates GNG?

Answer 1

Glucagon

Question 2

What hormone inhibits GNG?

Answer 2

Insulin

Question 3

What is used to make glucose during starvation and low levels of carbs?

Answer 3

Amino acids

Question 4

What is used to make glucose during exercise?

Answer 4

Lactic acid and alanine

Question 5

T/F: glycogen degradation happens prior to GNG

Answer 5

True

Question 6

T/F: GNG is the synthesis of glucose from non-carbohydrate precursors

Answer 6

True

Question 7

Why do RBC’s need glucose?

Answer 7

No mitochondria and no aerobic metabolism (no fat burning)

Question 8

Glucose requirements for the brain in g/day and kcal

Answer 8

100, 400

Question 9

90% of GNG happens in the…

Answer 9

Liver

Question 10

What are the three irreversible reactions in glycolysis?

Answer 10

Hexokinase (glucokinase), Phosphofructokinase, Pyruvate kinase

Question 11

What is the first obstacle in glycolysis?

Answer 11

Phophoenolpyruvate to pyruvate via Pyruvate Kinase

Question 12

What is the 1st half of the 1st obstacle in glycolysis?

Answer 12

Pyruvate to Oxaloacetate via Pyruvate carboxylase (coE Biotin)

Question 13

Pyruvate carboxylase is present in the mitochondria of … and …

Answer 13

liver and kidney

Question 14

Where is pyruvate carboxylase found where it DOESN’T SYNTHESIZE GLUCOSE?

Answer 14

MUSCLE

Question 15

Oxaloacetate needs to get to the cytosol via the…

Answer 15

malate shuttle

Question 16

1st obstacle, 2nd half happens in the ___ and ___. If Lactate is precursor the reaction only happens in the ____

Answer 16

cytosol and mitochondria, mitochondria

Question 17

Enzyme and coenzyme for Oxaloacetate to Phosphoenolpyruvate

Answer 17

PEP carboxykinase, Mg2+

Question 18

T/F: ATP then GTP is required for 1st obstacle

Answer 18

True

Question 19

Lactate to Pyruvate in cytosol yields ____

Answer 19

NADH

Question 20

What is the enzyme for the 2nd obstacle?

Answer 20

PFK (F6P->F1,6BP)

Question 21

What enzyme and co-enzyme is used to overcome the second obstacle?

Answer 21

Fructose-1, 6-bisphosphatase, Mg2+

Question 22

What is the enzyme for the 3rd obstacle?

Answer 22

Glucokinase (Glucose -> glucose-6-phosphate)

Question 23

What is the enzyme and coenzyme used to overcome the 3rd obstacle?

Answer 23

glucose 6 phosphatase, Mg2+

Question 24

Does the muscle have glucose-6-phosphatase?

Answer 24

No. Muscle does NOT release glucose. The Liver releases glucose

Question 25

What are three key enzymes for glycolysis?

Answer 25

Glucokinase, PFK, Pyruvate kinase

Question 26

What are three key enzymes for GNG?

Answer 26

Glu-6-phosphatase, Fru-1,6-bisphosphatase, and Pyruvate carboxylase

Question 27

What are the energy costs in ATP, GTP, and NADH in turning Glucose to Pyruvate?

Answer 27

4, 2, 2

Question 28

What are the listed substrates for gluconeogenesis?

Answer 28

Glycerol, Lactic Acid, a-ketoacids (Pyruvate, OAA, A-ketoglutarate)

Question 29

Muscle releases Lactate and is transported to the liver to become...

Answer 29

glucose

Question 30

In the Cori cycle, what are the steps that happen in the muscle?

Answer 30

Glycogen -> glucose 6P -> pyruvate -> Krebs and lactate (released to liver)

Question 31

In the Cori Cycle what are the steps that happen in the liver?

Answer 31

Lactate ->[lactacte dehydrogenase]-> pyruvate -> glucose (released to muscle)

Question 32

a-ketoacids are the carbon skeleton of ____

Answer 32

amino acids

Question 33

What are the primary source of glucose for GNG during rest and fasting periods?

Answer 33

a-ketoacids

Question 34

What is the glucose-alanine cycle? What happens and where? BASICALLY

Answer 34

Muscle takes in glucose, releases alanine, Liver takes in alanine, releases glucose.

Question 35

Fructose-2,6-bisphosphate stimulates ___ in the ___ and inhibits ___

Answer 35

Glycolysis, liver, GNG

Question 36

Glucagon stimulates GNG as well as ___ breakdown in the ____

Answer 36

glycogen, liver

Question 37

What are the three stimulators of GNG?

Answer 37

Glucagon, Acetyl CoA, Citrate

Question 38

What are the three inhibitors of GNG?

Answer 38

Glucose, Insulin, AMP, ADP, F-2,6-Bisphosphate