bich 2 exam 2

Question 1

draw the steps of gluceogenesis

Answer 1

glucose 6P –> glucose by glucose-6-phosphatase

fructose 1,6 bisphosphate –> fructose 6-phophate by fructose 1,6-bisphosphatase

pyruvate –> oxaloacetate –> phosphoenolpyruvate by pyruvate carboxylase and PEP carboxykinase

Question 2

draw glycogen synthesis

Answer 2

answer on doc

Question 3

draw glycogen catabolism

Answer 3

answer on doc

Question 4

draw TCA cycle

Answer 4

answer on doc

Question 5

draw oxaloacetate

Answer 5

answer on doc

Question 6

draw citrate

Answer 6

answer on doc

Question 7

draw isocitrate

Answer 7

answer on doc

Question 8

draw alpha-ketoglutarate

Answer 8

answer on doc

Question 9

draw succinyl-coA

Answer 9

answer on doc

Question 10

draw succinate

Answer 10

answer on doc

Question 11

draw fumarate

Answer 11

answer on doc

Question 12

draw malate

Answer 12

answer on doc

Question 13

draw pyruvate dehydrogenase reaction

Answer 13

answer on doc under TCA

Question 14

What is the purpose of the glyoxylate cycle?

Answer 14

It short cuts the TCA cycle so no carbon is lost as CO2.
ANABOLIC AND CATABOLIC. Produces NADH and FADH2 to power electron transport
intermediate for biosynthesis

Question 15

Glyoxylate pathway in plants:

Answer 15

occurs in glyoxysome
seeds oxidize fatty acids to acetylCoA and its used to glyoxylate pathways to support growth

glyoxylate shunt cannot use photosynthesis yet

Question 16

draw the glyoxylate pathway

Answer 16

isocitrate –> glyoxylate + succinate… glyoxylate –> malate (proceeds through TCA)

Question 17

what molecules can go in and out of the mitochondria?

Answer 17

pyruvate, citrate, malate

Question 18

what cannot go in and out of the mitochondria?

Answer 18

Acetyl CoA and oxaloacetate

Question 19

What are anaplerotic reactions?

Answer 19

reactions that fill up or replenish TCA intermediates

Question 20

TCA cycle is regulated by what?

Answer 20

NAD+/NADH, Acetyl CoA, ADP/ATP

Question 21

Committed step of TCA cycle:

Answer 21

pyruvate dehydrogenase

Question 22

Pyruvate dehydrogenase regulators

Answer 22

increase: NAD+, CoA
decrease: acetyl-CoA, NADH, ATP

Question 23

hexokinase I regulation

Answer 23

in brain tissue
inhibited by glucose 6P
expressed in most tissues other than liver dimer

Question 24

glucokinase regulation and purpose

Answer 24

induced by insulin.. need a high level of glucose for it to be active

soaks of excess glucose into liver for other pathways

Question 25

glucokinase vs glucose6-phophatase

Answer 25

Glucose 6-P works in the opposite direction of glucokinase. Not inhibited by G6P

Question 26

how are enzymes of glycolysis and gluconeogenesis would be regulated under a given set of conditions in a cell?

Question 27

what are the key regulated enzymes that partition glucose6-P between all the pathways?

Answer 27

Glycogen phosphorylase Glycogen Sythase Glucose 6P phosphatase phosphofructokinase Glucose 6P dehydrogenase

Question 28

Allosteric regulation of glycogen synthase

Answer 28

Allosteric activater: G6P inhibitor: cAMP depending phosphorylation

Question 29

Allosteric regulation of glycogen phosphorylase

Answer 29

Allosterically Activated by AMP Allosterically Inhibited By ATP, G6P

Question 30

Draw Hormonal regulation for glucagon of glycogen synthase and glycogen phosphorylase via phosphorylation

Answer 30

see doc

Question 31

Be able to describe why and how concentrations of NAD+/NAD, acetyl-CoA/CoA, and ADP/ATP regulate the TCA cycle, based on the energy or biosynthetic needs of a cell.

Question 32

isocitrate dehydrogenase regulation and why

Answer 32

Activators: ADP Inhibitors: NADH, ATP When activated citrate goes through TCA cycle when low ADP and high ATP goes to cytosol Step before isocitrate converts to alpha-ketoglutarate in the mitochondria and cannot be converted back. Before that it can be converted back to citrate and moved into the cytosol to make fatty acids, and steroids.

Question 33

E equation for half reactions

Answer 33

E = Eo + (RT/nF) ln(ox/red)

Question 34

How is E related to G

Answer 34

G= -nFE

Question 35

What does E stand for

Answer 35

standard reduction potential... tendency of chemical species to be reduced

Question 36

What direction will a reaction go if E is negative?

Answer 36

If G is negative, E is positive so spontaneous is positive E

Question 37

Recognized FAD, TPP, CoA, Lipoic Acid, Biotin

Answer 37

on doc

Question 38

How is FAD used?

Answer 38

It is used for regulation and can pick up two protons

Question 39

Phosphofructosekinase in glycolysis is regulated by:

Answer 39

inhibited by ATP, citrate activated by AMP, fructose 2,6-bisphospahte

Question 40

Fructose1,6-bisphosphate phosphatase regulation gluconeogenesis

Answer 40

Activated by citrate Inhibited by AMP, fructose 2,6bP

Question 41

pyruvate kinase regulation

Answer 41

Inhibited by ATP and alanine makes PEP available for gluconeogenesis

Question 42

Where all is G6P used?

Answer 42

glycogen, gluconeogenesis, glycolysis, pentose phosphate

Question 43

Glucose 6-P dehydrogenase (pentose phosphate shunt) regulation

Answer 43

inhibited by NADPH, fatty acyl-CoA

Question 44

Purposes of Pentose Phosphate Shunte

Answer 44

Generates NADPH for biosynthesis In cytosol Generate ribose 5-P which builds nucleic acids Products feed into glycolysis/ gluconeogenesis to convert glucose into pyruvate

Question 45

What reactions are anaplerotic?

Answer 45

Pyruvate carboxylase and Malic Enzyme

Question 46

Pyruvate carboxylase regulation

Answer 46

activated by acetyl CoA

Question 47

alpha ketoglutarate dehydrogenase regulation

Answer 47

Activated by AMP Inhibited by NADH and succinyl CoA

Question 48

Draw succinyl CoA synthase reaction

Answer 48

on doc

Question 49

draw pyruvate carboxylase

Answer 49

in spiral notebook

Question 50

Draw Hormonal regulation for insulin of glycogen synthase and glycogen phosphorylase via phosphorylation

Answer 50

on doc

Question 51

Look at transketolase reaction

Answer 51

on paper

Question 52

Look at transaldolase reaction

Answer 52

on paper