Lactate Shuttle, Gluconeogenesis and Regulation of Carbohydrate Metabolism Flashcards
(28 cards)
how many ATP come from one round of the krebs cycle
10
3 NADH+H ATP equivalent
7.5
1 FADH2 ATP equivalent
1.5
1 GTP/ATP ATP equivalent
1 ATP
oxidative phosphorylation net ATP
32 ATP
lactate forms when
hydrogens from NADH combine temporarily with pyruvate
when hydrogens from NADH combine temporarily with pyruvate, it frees up NAD to …
accept additional hydrogens generated in glycolysis
glycolytic flux in excess of mitochondrial capacity =
extra lactate production
what enzyme has the highest Vmax of any glycolytic enzyme
lactate dehydrogenase
the lactate shuttle suggests lactate may actually be fuel of choice during
exercise for heart and type I skeletal muscle fibers
lactate produced in type II …
transported to and used in oxidative tissue
main substrates that supply the carbon backbones needed for glucose synthesis
glycerol, lactate, and amino acids
gluconeogenesis is somewhat the reverse of what other metabolic process but with what change
glycolysis; special enzymes are needed to work backwards
gluconeogensis occurs mainly in the
liver
the cori cycle utilizes _____ to produce ___
lactate; glucose
the glucose-alanine cycle ___ ____ to produce ___
degrades protein; glucose
both the cori cycle and the glucose alanine cycle do what
recycle glucose
cori cycle steps
lactate from venous circulation —-> pyruvate —-> glucose —-> glycogen or arterial bloodstream
glucose alanine cycle steps
alanine —> pyruvate —-> glucose
by products of alanine converting to pyruvate
NH2 —> urea
carbohydrate metabolism is regulated by
- concentrations of glycolytic enzymes hexokinase, PFK, and pyruvate kinase
- oxygen
enzyme inhibitors
ATP & NADH
enzyme activators
ADP and NAD
rate limiting ezyme of glycolysis
PFK
