Biochem: Glycolysis/gluconeogenesis

Front 1

Hexokinase/Glucokinase

Back 1

Glc -> Glc-6-phos

*ATP -> ADP
*Regulated step

Front 2

Name two reactions where ATP is hydrolyzed (including enzymes)

Back 2

Glc -> Glc-6-phos by hexokinase, glucokinase

Fruc-6-phos -> Fruc-1,6-bisph by phosphofructokinase

Front 3

Glc -> Glc-6-phos

Back 3

Hexokinase/Glucokinase

Front 4

Phosphoglucose isomerase

Back 4

Glc-6-phos -> Frc-6-phos

Front 5

Glc-6-phos -> Frc-6-phos

Back 5

Phosphoglucose isomerase

Front 6

Phosphofructokinase (PFK-1)

Back 6

Fruc-6-phos -> Fruc-1,6-bisphos

*ATP -> ADP
*Regulated step

Front 7

What molecules activate PFK-1?

Back 7

AMP, ADP, Pi, Fructose-2,6-bisphosphate

Front 8

Fruc-6-phos -> Fruc-1,6-bisphos

Back 8

Phosphofructokinase (PFK-1)

Front 9

Phosphofructokinase (PFK-2)

Back 9

Fruc-6-phos -> Fruc,2,6-bisphos

*Regulatory molecule ONLY
*Stimulates glycolysis

Front 10

Fruc-6-phos -> Fruc,2,6-bisphos

Back 10

Phosphofructokinase (PFK-2)

Front 11

What molecules inhibit PFK-1?

Back 11

ATP, citrate, H+

Front 12

Fructose-bisphosphatase-2

Back 12

Fruc-2,6-bisphos -> Fruc-6-phos

*Conversion inactivates glycolysis

Front 13

Fruc-2,6-bisphos -> Fruc-6-phos

Back 13

Fructose-bisphosphatase-2

Front 14

Aldolase

Back 14

Fruc-1,6-bisphos -> DHAP, G3P

Front 15

Fruc-1,6-bisphos -> DHAP, G3P

Back 15

Aldolase

Front 16

Triosephosphate isomerase

Back 16

DHAP <-> G3P

Front 17

DHAP <-> G3P

Back 17

Triosephosphate isomerase

Front 18

G3P -> 1,3-Bisphosphoglycerate

* Produces 2 NAD -> 2 NADH

Back 18

Glyceraldehyde-3-phosphate dehydrogenase

Front 19

Glyceraldehyde-3-phosphate dehydrogenase

Back 19

G3P -> 1,3-Bisphosphoglycerate

*Converts 2 NAD -> 2 NADH

Front 20

What factors (i.e. not innate molecules) disrupt glyceraldehyde-3-phosphate dehydrogenase activity?

Back 20

Heavy metals, peroxynitrite, arsenate

Front 21

Phosphoglycerate kinase

Back 21

1,3-bisphosphoglycerate -> 3-phosphoglycerate

*Produces 2 ATP
*Substrate level phosphorylation

Front 22

1,3-bisphosphoglycerate -> 3-phosphoglycerate

Back 22

Phosphoglycerate kinase

Front 23

Phosphoglycerate mutase

Back 23

3-phosphoglycerate -> 2-phosphoglycerate

Front 24

3-phosphoglycerate -> 2-phosphoglycerate

Back 24

Phosphoglycerate mutase

Front 25

Enolase

Back 25

2-phosphoglycerate -> PEP

Front 26

2-phosphoglycerate -> PEP

Back 26

Enolase

Front 27

Pyruvate kinase

Back 27

PEP -> Pyruvate

Front 28

PEP -> Pyruvate

Back 28

Pyruvate

Front 29

What molecules inhibit pyruvate kinase?

Back 29

High ATP, alanine

Front 30

What is the effect of phosphorylation of pyruvate kinase? Dephosphorylation? Where does this occur?

Back 30

Inactivates; Restores; Liver

Front 31

What is the effect of insulin on glycolysis?

Back 31

Promotes glycolysis

Insulin promotes dephosphorylation of PFK2/FBPase-2 complex, activating PKF2, deactivating FBPase-2

PFK2 produces more F-2,6-BP, activating glycolysis

Front 32

What is the effect of glucagon on glycolysis?

Back 32

Inhibits glycolysis

Glucagon mediates phosphorylation of PFK2/FBPase-2 complex via cAMP, activating FBPase-2

FBPase-2 converts F-2,6-BP back to F-6-P, preventing glycolysis stimulatoin

Front 33

Where does the fructose-1-pathway occur?

Back 33

Liver

Front 34

Fructokinase

Back 34

Fructose -> Fruc-1-phos

Front 35

Fructose -> Fruc-1-phos

Back 35

Fructokinase

Front 36

Fructose-1-phosphate adolase

Back 36

Fruc-1-phos -> DHAP, Glyceraldehyde

Front 37

Fruc-1-phos -> DHAP, Glyceraldehyde

Back 37

Fructose-1-phosphate adolase

Front 38

Triose kinase

Back 38

Glyceraldehyde -> G3P

* Converts ATP -> ADP

Front 39

Glyceraldehyde -> G3P

Back 39

Triose kinase

Front 40

Galactokinase

Back 40

Galactose -> Galac-1-phos

Front 41

Galactose -> Galac-1-phos

Back 41

Galactokinase

Front 42

Galactose-1-phosphate uridyl transferase

Back 42

Galac-1-phos + UDP-glc -> UDP-galactose + Glc-1-phos

Front 43

UDP-glucose pyrophosphorylase

Back 43

UDP-glucose -> Glucose-1-phosphate

Front 44

What components are required for pyruvate carboxylase activity?

Back 44

ATP used to attach CO2 to biotin, required for activity

Front 45

Pyruvate carboxylase

Back 45

Pyruvate -> OAA

*Irreversible step
*Requires activation with CO2, ATP and biotin

Front 46

Pyruvate -> OAA

Back 46

Pyruvate carboxylase

Front 47

OAA -> Malate -> OAA

Back 47

Mitochondrial malate dehydrogenase

Cytosolic malate dehydrogenase

Front 48

Mitochondrial/cytosolic malate dehydrogenase

Back 48

OAA <-> Malate

Front 49

PEP carboxykinase

Back 49

OAA -> PEP

Front 50

OAA -> PEP

Back 50

PEP carboxykinase

Front 51

Fructose-1,6-bisphosphatase

Back 51

Fruc-1,6-BP -> Fruc-6-phos

Front 52

Fruc-1,6-BP -> Fruc-6-phos

Back 52

Fructose-1,6-bisphosphatase

Front 53

Glucose-6-phosphatase

Back 53

Glc-6-phos -> Glucose

*In liver ONLY

Front 54

What effect does glucagon have on gluconeogenesis?

Back 54

Increases gluconeogenesis to maintain blood glucose levels

Glucagon, through cAMP cascade, phosphorylates PFK2/FBPase-2 complex.

Phosphorylation deactivates PFK2, activates FBPase-2

FBPase-2 converts F-2,6-BP back to F-6-P, reduces inhibition of FBP-1 (fruc-1,6,-bisphosphatase)

Front 55

Lactate dehydrogenase

Back 55

Lactate -> Pyruvate

*Beginning of gluconeogenesis from lactate

Front 56

Mitochondrial aspartate aminotransferase (AAT)

Back 56

OAA + Glu -> Asp + alpha-ketoglutarate

Front 57

OAA + Glu -> Asp + alpha-ketoglutarate

Back 57

Mitochondrial aspartate aminotransferase (AAT)

Front 58

Asp + alpha-ketoglutarate -> OAA + Glu

Back 58

Cytosolic aspartate aminotransferase

Front 59

Cytosolic aspartate aminotransferase

Back 59

Asp + alpha-ketoglutarate -> OAA + Glu