TBL 9 Flashcards
Glycolysis and PPP
Glycolysis Rate Determining Steps
hexokinase and glucokinase (liver)
PFK-1 and PFK-2 (glycolysis)
pyruvate kinase,
lactate dehydrogenase (fermentation)
Regulators of Glycolysis: Activators
ADP: sign of low energy
AMP: Stress signal
Calcium: signaling and insulin connection
F-1,6-bisphosphate and F-2,6-bisphosphate: allosteric
Regulation of Glycolysis: inhibitors
ATP: sign of high energy
Citrate: downstream product ie road block
Glucose-6-Phosphate: road block
Lactogen
mimics growth hormone
GH opposes insulin action and increases blood glucose. Glucokinase activity reduced. Mechanism of gestational diabetes
Rate Limiting Enzyme of Glycolysis
PFK-1
Activated by: AMP and F-2,6-BP
Inhibited by: ATP and Citrate
produces: Fructose-1,6-Bisphosphate
Fructose-2,6-Bisphosphate (Fed State)
Insulin, PFK2 ON, F-2,6-BP made, activating PFK-1. Drives glucose to pyruvate
Fructose-2,6-Bisphosphate (Fasting State)
Glucagon activates Protein Kinase A. Phosphorylation of PKA activates FBPase-1. Glucose synthesis in the liver
Pyruvate Kinase Deficiency
causes hemolytic anemia
low ATP, loss of ion balance osmotic fragility, swelling and lysis
echinocytes
increased 2,3-BPG alters Hgb binding
Lactic Acidosis
excess lactate released by cells during glycolysis
Causes: poor oxygen support, LDH dysfunction or other metabolic conditions
NADPH uses
Anabolic reactions: FA synthesis, adrenal cortex steroid hormone, mammary gland
Glutathione reduction: RBC erythrocytes
Drug Detox: liver CYP system
Immune Cells: oxidizes pathogens
PPP oxidative (irreversible) phase
G6PD
6-phosphogluconate dehydrogenase
PPP non-oxidative
reversible phase
Transketolase
Transaldolase
outcomes: purine and pyrimidine synthesis
F-6-P back to glycolysis
G-3-P to lipids
other rings to make other sugar products
Transketolase
transfers 2 carbons
requires TPP (vitamin B1)
Transaldolase
transfers 3 carbons
