Metabolism 4 - (Regulating gluconeogenesis + glycolysis) Flashcards
Which steps are regulated in gluconeogenesis?
Same steps as glycolysis but in reverse
= 1, 7 + 10
What are the 4 mechanisms of regulating gluconeogenesis?
> substrate availability
conc of enzymes
allosteric regulation
covalent modification
What are the +ve and -ve controls of
fructose 1,6 bisphosphate
–> F6P?
+ve = Fructose 2,6 bisphosphate
& AMP
-ve = citrate
What are the +ve and -ve controls of phosphoenolpyruvate –> pyruvate?
+ve = Feed-forward activation by F 1,6 bisphosphate
-ve = ATP + Acetyl CoA
Glucose G6P
Which enzyme is used in glycolysis?
Which enzyme is used in gluconeogenesis?
Hexokinase
Glucose 6 phosphatase
F6P Fructose 1,6 bisphosphate
Which enzyme is used in glycolysis?
Which enzyme is used gluconeogenesis?
PFK1
Fructose 1,6 bisphosphatase
Phosphoenolpyruvate pyruvate
Which enzyme is used in glycolysis?
Which enzyme is used in gluconeogenesis?
Pyruvate kinase
Phosphoenolpyruvate carboxykinase
oxaloacetate
+ pyruvate carboxylase
How does insulin affect gluconeogenic genes?
Downregulates expression
How is glycolysis + gluconeogenesis affected by low blood glucose?
Release of glucagon
- > decreased glycolysis
- > increased gluconeogenesis
How is glycolysis + gluconeogenesis affected by high blood glucose?
Release of insulin
- > increased glycolysis
- > decreased gluconeogenesis
What is a futile cycle?
When 2 opposing pathways occur at the same time at the same rate
= waste of energy
= no net gain
