Flashcards in Enzymes as Biological Catalysts Deck (59)
enzymes speed up the rate at which a reaction reaches _____
Enzymes DO NOT affect the equilibrium ____ of a reaction
what are enzymes made of?
mostly proteins - exceptions are some types of RNA - ribozymes are catalysts
enzymes can increase the rate of a reaction by a factor of up to __
Enzymes specifically bind and stabilise the ____ ___
what is the transition state?
the reaction intermediate species which has the greatest free energy
how do enzymes reduce the activation energy ?
they provide alternative pathways
what is glycogen storage disease?
an enzyme deficiency that results in failure of
glycogen to enter transition “phosphorylated” state
glycogen storage disease is caused by Defective ____ synthesis/breakdown in muscle, ____ & kidney
Defective glycogen synthesis/breakdown in muscle, liver & kidney
what is the most common enzyme to be defective in glycogen storage diseasE>
glucose 6 phosphate
what does a defect in glucose 6 phophate cause?
von gierke's disease
what are the symptoms of von gierks (5)
- skin and mouth ulcers
- bacterial and fungal infection
- bowel inflammation and irritability
why do you get hypoglycaemia if you dont have glucose 6 - phosphate
you cannot convert glycogen to glucose
what is the treatment for glycogen storage disease?
- slow release glucose meal
- feed little and often
why are people with von gierks given corn starch ?
it is hard to metabolise so prevents hypoglycaemia
Catalytic activity of many enzymes depends on presence of small molecules, called ____ or____
cofactors or coenzymes.
what are cofactors ?
what are coenzymes?
Metal cofactors form a ____ _____ ____ in the enzyme.
metal co-ordination centre
what can an enzyme be referred to if it has a metal co-ordination centre?
Coenzymes mostly associate with the enzyme only ____
Coenzymes change ____ or-_____ during the course of the reaction, but are ______.
Coenzymes change charge or structure during the course of the reaction, but are regenerated.
what are tightly bound coenzymes caused?
what is an enzyme without a cofactor called?
what is an enzyme with a cofactor called?
apoenzyme + cofactor =
give ezamples of some cofactors?
metal ions - zinc iron
metal ions are involved in ____ reactions
many coenzymes are derived from ____