Carbohydrates 3 Flashcards
Where does a allosteric regulator bind?
site other than the active site
Other than allosteric regulation how else can a an enzyme be regulated?
phosphorylation and de phosphorylation
Which step are key to regulation?
the irreversible ones
What inhibits catabolic processes?
High energy signals
ATP, NADH, FADH2
What activates catabolic processes?
low energy signals
ADP, AM, NAD, FAD
Explain how hormones activate or inhibit processes.
Give an example
hormone bind receptor
activate protein kinase or protein phosphatase
Alter target protein conformation
increase or decrease enzyme activity
Adrenaline–> protein kinase A –>phosphorylase kinase–>glycogen phosphorylase –> glycogen breakdown
Committing step in glycolysis?
phosphofructokinase-1
fructose-1-phosphate to fructose-1,6- bisphosphate
What regulates hexokinase?
substrate inhibition by glucose 6 phosphate
What regulates phosphofructokinase-1?
inhibited: ATP and glucagon
activated by: AMP and insulin
What regulates pyruvate kinase?
Activate- insulin
inhibit- glucagon
How does insulin activate enzymes?
protein phosphatase 1 activated to de phosphorylate enzymes increasing activity
How does glucagon activate enzymes?
protein kinase A activated to phosphorylate them reducing activity
