Gluconeogenesis

Question 1

what types of bonds are formed between glucose to make glycogen

Answer 1

a-1,4-glycosidic and a-1,6 glycosidic linkages

Question 2

enzymes associated with glycogenolysis

Answer 2

glycogen phosphorylase (PLP)*, phosphoglucomutase, 4a-glucanotransferase, amylo-1,6-glucosidase

Question 3

what regulates glycogen phosphorylase?

Answer 3

AMP (+), ATP (-), glucagon (+), insulin (-), glucose (-)

Question 4

what limits the formation of glucose in glycogenolysis

Answer 4

UDP-glucose

Question 5

glycogenolysis

Answer 5

breakdown of glycogen

Question 6

glycogenesis

Answer 6

formation of glycogen

Question 7

what enzymes are associated with glycogenesis

Answer 7

UDP-glucose phosphorylase, glycogen synthase

Question 8

what regulates glycogen synthase

Answer 8

glucagon (-), insulin (+), glucose (+), UDP-glucose phosphorylase (+)

Question 9

what enzyme converts between glucose and glucose 6 phosphate

Answer 9

glucose 6 phosphatase

Question 10

what is the transporter that moves glucose into the ER

Answer 10

GLUT7

Question 11

which enzyme converts fructose 6 phosphate to fructose 1,6 bisphosphate

Answer 11

fructose 1,6 bisphosphatase

Question 12

what regulates fructose 1,6 bisphosphatase

Answer 12

AMP (-), F26bP (-)

Question 13

where does glycerol 3 phosphate in the ER come from

Answer 13

triglycerols are broken down into glycerol and 3 fatty acids, which are made into glycerol 3 phosphate via glycerol kinase

Question 14

what turns glycerol 3 phosphate into dihydroxyacetonephosphate

Answer 14

glycerol 3 phosphate DH, using either Q or NAD+ as the cofactor

Question 15

how does pyruvate get into the mitochondria

Answer 15

a pyruvate transporter

Question 16

where does the pyruvate in the cytosol come from

Answer 16

1) lactate is converted to pyruvate via liver LDH
2) amino acids (ex: Ala) are converted to pyruvate via transmaminase

Question 17

what converts pyruvate to oxaloacetate

Answer 17

pyruvate carboxylase (biotin)

Question 18

what is required for the reaction of pyruvate to oxaloacetate

Answer 18

bicarbonate and ATP

Question 19

how is oxaloacetate converted into PEP

Answer 19

PEP carboxykinase

Question 20

what is formed as a result of the reaction of oxaloacetate to PEP

Answer 20

GDP and CO2

Question 21

how is oxaloacetate formed without pyruvate

Answer 21

odd chain fatty acids are converted to propionate and then oxaloacetate

Question 22

what regulates pyruvate carboxylase

Answer 22

acetyl CoA (+)

Question 23

what is used/produced in the reaction of F16bP to F6P

Answer 23

H2O is used and Pi is produced

Question 24

what end of glycogen does glycogen phosphorylase (PLP) remove glucose from

Answer 24

nonreducing end

Question 25

what transporter moves glucose into the muscle or adipose tissue

Answer 25

GLUT4

Question 26

where is insulin produced

Answer 26

beta cells of the pancreas

Question 27

what are the two ways lactate can be made into glucose

Answer 27

1) pyruvate -> oxaloacetate -> aspaprtate ->… 2) pyruvate -> oxaloactetate -> PEP -> …

Question 28

what two molecules can glucose be synthesized from

Answer 28

lactate or pyruvate

Question 29

where is PEPCK found

Answer 29

mitochondria or cytosol

Question 30

where is pyruvate carboxylase found

Answer 30

mitochondria

Question 31

where is glucose 6 phosphatase found

Answer 31

ER membrane

Question 32

where are most gluconeogenesis enzymes found

Answer 32

cytosol

Question 33

how is glycerol used in gluconeogensis

Answer 33

converted to dihydroxyacetonephosphate via glycerol 3 phosphate dehydrogenase with 1. NAD+ -> NADH or 2. Q->QH2 in the intermembrane mitochondrial space

Question 34

what is the cori cycle

Answer 34

- the interaction of glycolysis in the muscles and gluconeogenesis in the liver - glucose from the liver is given to the muscles, which turns it into lactate to be remade into glucose in the liver

Question 35

what is the intermediate of the conversion of glucose 6 phosphate to glucose via glucose 6 phosphatase

Answer 35

phosphoglucohistidine

Question 36

which hormone activates PFK2

Answer 36

insulin

Question 37

what catalyzes formation of F26bP

Answer 37

PFK2

Question 38

in which state is more F26bP made

Answer 38

fed (F26bP -> acetyl CoA -> TG)

Question 39

how does acetyl CoA activate pyruvate carboxylase

Answer 39

excess acetyl CoA accumulates from fatty acid oxidation, which indicates abundant energy and signals the production of oxaloacetate in gluconeogenesis

Question 40

what are the intermediates of the pyruvate carboxylase rxn

Answer 40

carboxy phosphate, carboxybiotinyl enzyme, pyruvate enolate

Question 41

which enzyme converts pyruvate to oxaloacetate

Answer 41

pyruvate carboxylase (biotin)

Question 42

which enzymes are activated/deactivated in the insulin cascade event

Answer 42

activated: PFK2, protein phosphatase 1, glycogen synthase deactivated: phosphorylase kinase, glycogen phosphorylase

Question 43

what hormone triggers the synthesis of glycogen

Answer 43

insulin

Question 44

which hormones trigger the breakdown of glycogen

Answer 44

epinepherine and glucagon

Question 45

what activates adenyl cyclase

Answer 45

Gprotein coupled receptor

Question 46

what makes cAMP

Answer 46

adenyl cyclase

Question 47

what activates protein kinase A

Answer 47

cAMP

Question 48

in the glucagon/epinepherine cascade event, which enzymes are activated/deactivated

Answer 48

activated: protein kinase A, phosphorylase kinase, glucagon phosphorylase deactivated: glycogen synthase

Question 49

what is the intermediate of the glycogen pyrophosphorylase rxn

Answer 49

half chair oxonium ion

Question 50

which cells have the highest concentration of glucagon receptors

Answer 50

liver cells

Question 51

what regulates glucagon secretion

Answer 51

alpha pancreas cells

Question 52

what is the difference between glycogen phosphorylase A and B

Answer 52

phosphorylase A: active form (-OH) phosphorylase B: inactive form (-PO3)

Question 53

what is a nonreducing end of a molecule

Answer 53

the ends of the molecule farthest from C1; contain acetal groups rather than a aldehyde or hemiacetal groups

Question 54

which type of linkages does glycogen phosphorylase work on

Answer 54

a-1,4-glycosidic linkages