enzymes Flashcards
1
Q
definition of a catalyst?
A
a chemical which increases the rate of reaction without being used up itself in the reaction
2
Q
enzymes are __________ __________
A
biological catalysts
3
Q
true or false: catalysts change after a reaction and so can’t catalyse more reactions
A
false
4
Q
explain the lock and key theory for how enzymes work
A
- substrate & enzyme collide
- substrate binds to active site of enzyme
- binding to active site strains chemical bonds in substrate molecules & so the reaction occurs by an alternative pathway with a lower activation energy
- once reaction occurred, products don’t fit active site’s shape as well as substrates did, so they’re released
- after reaction, enzyme molecule free to catalyse next reaction
5
Q
why can each enzyme only catalyse one reaction?
A
because active site of a particular enzyme has a specific shape which is complementary to the shape of the substrate(s)
6
Q
A
