Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

17 Cards in this Set

  • Front
  • Back
reverse of glycolysis EXCEPT there are three irreversible reactions that must be overcome through the use of different gluconeogenic enzymes
usually go from glucose to pyruvate, now want to start with pyruvate/aa/lactate and work backwards

glycolysis backwards
pyruvate--> PEP--. 2-phosphoglycerate-->3phosphoglycerate-->1,3bPglycerate --> GAP --> F1,6bP --> F6P --> G6P --> G
Bypass step 1
pyruvate + ATP + HCO3 --> oxaloacetate (is transported out of mito via malate shuttle) + GTP --> PEP + CO2 + Pi

Coupling of carboxy then decarboxy reactions

Pyruvate carboxylase, then PEPCK (PEP carboxy kinase)

NOTE: anapleurotic because makes OAA a TCA interm
Describe Pyruvate carboxylase
In mito

biotin coenz cov linked to lys which allows it to swing between active sites in the enz

biotin attaches a CO2 in one active site, swings and transfers carboxy group to pyruvate in another active site

can also carboxlate acetyl and propionyl
Pyruvate Carboxylase regulation

pyruvate kinase control in comparison?
Allosteric activation: Acetyl CoA (a product of FA metabolism, it also inhibits PDH by activating PDH kinase)

makes sense if gluc is low, FA will be metabolized and want gluconeogenesis, not PDH leading to TCa cycle

NOTE: allosterically inhibited by aspartate, inhib by ADP

Pyruvate kinase is pos F16P and neg ATP
Steps leading up to Bypass 2
PEP --> 2 phosphoglycerate-->3phosphoglycerate--> 1,3bPglycerate-->GAP-->F1,6P
Bypass step 2
F1,6bP --> F6P

hydrolising the phosphate ester

F1,6bphosphatase, uses H2O
regulation of F1,6bPhosphatase
inhibited allosterically by F2,6P and AMP

F2,6P activates reverse reaction (therefore its a reciprocal regulator)

activated by citrate

NOTE: PFK1 is positively activated by AMP and F26P and neg inhib by ATP and citrate
Bypass 3
G6P --> G

hydrolyzed by glucose 6Phosphatase
membrane bound in ER, only found in liver and kidney, so no other tissue can release free glucose,

high Km, will only function when G6P is high

utilizes water
Glucose 6-Phosphatase and the ER
G6P transported into ER where enz can hydrolyze it, Gluc and Pi are in lumen and need to be transported back out
Glycogen storage disease Ia
deficiency of glucose-6-phosphatase
gluconeogenesis overall
converts two pyruvate to one glucose, consuming 2 NADH amd 6 ATP/GTP

vs glycolysis which makes 2 nadh and 2 ATP
how do you get NADH in cytosol to fuel gluconeogenesis
See page 57

pyruvate into mit
pyruvate to OAA
OAA to malate producing NAD
malate out
malate to OAA producing NADH

important to have NADH in cytosol for use in gluconeogenesis

normally NADH/NAD cytosolic ratio is usually very low
LACTATE and gluconeogenesis (from RBC and muscle)
lactate is converted to pyruvate in the cytosol yeilding NADH (no need for transport to make cytosolic NADH)

pyruvate is then shuttled into cell goes through the normal pathway (--> OAA via pyruvate carboxylase) --> PEP via PEPCK happens in mito! as oppose to in cytosol of regular pyruvate metab
PEP can leave cell or OAA can --> asp via transamination, asp can leave directly

OAA in mito can leave directly via asp or can be converted to PEP by PEP carboxykinase which can be exported to cytosol
alanine makes?
glutamine makes?
ala --> pyruvate
glutamine --> alphaketo glutarate
The Cori cycle
glycolysis in muscle makes 2ATP and 2 Lactate

those lactates go to liver

liver puts two lactates through gluconeogenesis using 6ATP to make glucose

glucose is then released
how much ATP is required for gluconeogenesis in liver?
how much ATP is generated from gluc in muscle
6ATP required to make glucose in liver and 2NADH

2ATP generated from glucose in anaerobic muscle/ 36ATP in aerobic