ESE Flashcards
Adrenalin triggering glycogen break down in skeletal muscle
Adrenalin activates adenylate Cyclase leading to cAMP synthesis
cAMP activates protein kinase A
Protein kinase A phosphorylates phosphorylase kinase making it active
Which in turn phosphorylates glycogen phosphorylase
Which removes the terminal glucose residue from the non reduce end of glycogen
Metabolic fates of glucose in fed liver
Increase transport into liver by GLUT2
Glucose phosphorylates to glucose-6-phosphate and trapped in liver
Increased glycolysis
Increased glycogen synthesis
Role of glycogenin
To synthesise new glycogen molecules
Cori cycle
Provide glucose to liver in starved state
Glucose converted to lactose in SM
Transported to liver
Fatty acids in liver broken down to CO2 & H20 to produce ATP to synthesise glucose from lactose
Glyoxylate cycle
2 unique enzymes, isocitrate lyase and Malate synthase allow for the 2 oxidative decarboxylation steps of the TCA cycle to be bypassed. Net gain of carbon from TCA cycle
Ketogenic amino acids
Metabolised to either acetyl coA or acetoacetyl coA
Glucogenic amino acids
Metabolised to pyruvate or a TCA cycle intermediate
Why can’t ketogenic amino acids serve as gluconeogenic precursors?
Acetyl coA must renter the TCA cycle and both carbons are lost as CO2
Competitive
Vmax: no change
Km: increase
Noncompetitive
Vmax: decrease
Km: no change
Uncompetitive
Vmax: decrease
Km: decrease
3 organelles in glycolate pathway
Chloroplast, peroxisome, mitochondria
PPP REGULATION
Oxidative phase: NADPH negatively regulates glucose-6-phosphate dehydrogenase
Nonoxidative: substrate concentration drives reactions
Transketolase
OH group at C3 on left
Transaldolase
OH group C4 right
