Quiz 3 Gluconeogenesis Flashcards Preview

Biochem 2 > Quiz 3 Gluconeogenesis > Flashcards

Flashcards in Quiz 3 Gluconeogenesis Deck (33)
Loading flashcards...
1

Pathway that makes glucose?

Gluconeogenesis

2

Hormone that stimulates gluconeogenesis (low blood glucose)

Glucagon

3

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

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

4

Is Glycolysis reversible? If not what pathway is used?

No...gluconeogenesis

5

Gluconeogenesis mainly takes place in the?

Liver, also some in renal cortex and small intestine

6

What three things are need to make gluconeogenesis favorable?

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

7

Glycolysis irreversible reactions?

Hexo or glucokinase, Phosphofructokinase, pyruvate kinase

8

What is considered the first obstacle?

Pyruvate Kinase from glycolysis

9

What are the reactants of pyruvate kinase

Phosphophenolpyruvate + ADP

10

What are the products of Pyruvate Kinase?

Pyruvate + ATP

11

What enzyme is used to overcome the first obstacle?

Pyruvate Carboxylase with coenzyme biotin

12

Reactants of (1st half) pyruvate carboxylase?

Pyruvate + ATP + CO2 + H2O

13

Products of pyruvate carboxylase?

ADP + Oxaloacetate

14

Where is pyruvate carboxylase present?

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

15

Pyruvate Carboxylase uses what two things as precursors?

Pyruvate or alanine

16

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

Cytosol, gets there via the malate shuttle

17

Pyruvate carboxylase is regulated by?

Acetyl CoA (this stimulates pyruvate carboxylase)

18

What is the second half of overcoming the first obstacle?

PEP carboxykinase (this is Mg2+ dependent)

19

Reactants of PEP carboxykinase?

Oxaloacetate + GTP

20

Products of PEP carboxykinase?

Phosphophenolpyruvate + CO2 + GDP

21

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

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

22

Lactate to pyruvate in the cytosol yields?

NADH

23

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

Mitochondria

24

What is considered the 2nd obstacle?

Phosphofructokinase (PFK) from glycolysis

25

How do we overcome the 2nd obstacle?

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

26

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

Fructose-1,6-bisphosphate + H2O

27

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

Fructose-6-phosphate + Pi

28

What is considered the 3rd obstacle in glycolysis?

Glucokinase

29

What enzyme is used to overcome the 3rd obstacle?

Glucose-6-phosphatase (Mg2+ dependent)

30

What are the reactants of glucose 6 phosphatase

Glucose-6-phosphate + H20

31

What are the products of glucose 6 phosphatase?

Glucose + Pi

32

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

NO, glucose remains trapped in the muscle.

33

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

6, (4 ATP and 2 GTP), and 2 NADH’s