Quiz 3 Gluconeogenesis

Question 1

Pathway that makes glucose?

Answer 1

Gluconeogenesis

Question 2

Hormone that stimulates gluconeogenesis (low blood glucose)

Answer 2

Glucagon

Question 3

What is used to make glucose in, Starvation? Low / no carbs? Exercise?

Answer 3

Starvation = amino acids, Low carb = amino acids, exercise = lactate and alanine.

Question 4

Is Glycolysis reversible? If not what pathway is used?

Answer 4

No…gluconeogenesis

Question 5

Gluconeogenesis mainly takes place in the?

Answer 5

Liver, also some in renal cortex and small intestine

Question 6

What three things are need to make gluconeogenesis favorable?

Answer 6

Alternative enzymes, coupled reactions, and ATP (or equivalent)

Question 7

Glycolysis irreversible reactions?

Answer 7

Hexo or glucokinase, Phosphofructokinase, pyruvate kinase

Question 8

What is considered the first obstacle?

Answer 8

Pyruvate Kinase from glycolysis

Question 9

What are the reactants of pyruvate kinase

Answer 9

Phosphophenolpyruvate + ADP

Question 10

What are the products of Pyruvate Kinase?

Answer 10

Pyruvate + ATP

Question 11

What enzyme is used to overcome the first obstacle?

Answer 11

Pyruvate Carboxylase with coenzyme biotin

Question 12

Reactants of (1st half) pyruvate carboxylase?

Answer 12

Pyruvate + ATP + CO2 + H2O

Question 13

Products of pyruvate carboxylase?

Answer 13

ADP + Oxaloacetate

Question 14

Where is pyruvate carboxylase present?

Answer 14

Liver and kidney (also present in the muscle but does nothing with synthesizing glucose)

Question 15

Pyruvate Carboxylase uses what two things as precursors?

Answer 15

Pyruvate or alanine

Question 16

Where does Oxaloacetate need to get? How does it get there?

Answer 16

Cytosol, gets there via the malate shuttle

Question 17

Pyruvate carboxylase is regulated by?

Answer 17

Acetyl CoA (this stimulates pyruvate carboxylase)

Question 18

What is the second half of overcoming the first obstacle?

Answer 18

PEP carboxykinase (this is Mg2+ dependent)

Question 19

Reactants of PEP carboxykinase?

Answer 19

Oxaloacetate + GTP

Question 20

Products of PEP carboxykinase?

Answer 20

Phosphophenolpyruvate + CO2 + GDP

Question 21

How many high energy molecules were required to overcome the first obstacle?

Answer 21

2 (ATP in the first half, and GTP with the second half)

Question 22

Lactate to pyruvate in the cytosol yields?

Answer 22

NADH

Question 23

Where does pyruvate carboxylase and PEP carboxykinase occur when lacate is the precursor??

Answer 23

Mitochondria

Question 24

What is considered the 2nd obstacle?

Answer 24

Phosphofructokinase (PFK) from glycolysis

Question 25

How do we overcome the 2nd obstacle?

Answer 25

Fructose-1,6-bisphosphatase (Mg2+ dependent)

Question 26

What are the reactants of Fructose-1,6-bisphosphatase?

Answer 26

Fructose-1,6-bisphosphate + H2O

Question 27

What are the products Fructose-1,6-bisphosphatase?

Answer 27

Fructose-6-phosphate + Pi

Question 28

What is considered the 3rd obstacle in glycolysis?

Answer 28

Glucokinase

Question 29

What enzyme is used to overcome the 3rd obstacle?

Answer 29

Glucose-6-phosphatase (Mg2+ dependent)

Question 30

What are the reactants of glucose 6 phosphatase

Answer 30

Glucose-6-phosphate + H20

Question 31

What are the products of glucose 6 phosphatase?

Answer 31

Glucose + Pi

Question 32

Again, does the muscle have glucose-6-phosphatase?

Answer 32

NO, glucose remains trapped in the muscle.

Question 33

For each glucose formed from pyruvate, how many high energy phosphate groups are used? How many NADH’S?

Answer 33

6, (4 ATP and 2 GTP), and 2 NADH’s