Enzymes Flashcards
1
Q
what is a catalyst?
A
a catalyst is a chemical which increases the rate of a reaction without being used up itself in the reaction
2
Q
what is an enzyme?
A
a biological catalyst
3
Q
how does an enzyme work (lock n key theory)?
A
- the substrate and enzyme collide.
- the substrate binds to the active site of the enzyme.
- binding to the active site strains the chemical bonds in the substrate molecules and so the
reaction occurs by an alternative pathway with a lower activation energy (the energy needed for a
reaction to occur). - once the reaction has occurred the products do not fit the active site’s shape as well as the
substrate did, so they are released. - after the reaction the enzyme molecule is free to catalyse the next reaction
4
Q
how many reactions can each enzyme molecule catalyse?
A
one
5
Q
how does temperature affect enzymes?
A
- the higher the temperature, the higher the kinetic energy
- this makes them move faster meaning more successful collisions
6
Q
what happens when an enzyme is denatured?
A
the active site changes shape and is no longer complementary to the substrate
7
Q
how can an enzyme get denatured?
A
- high temperature
- changes of pH
8
Q
how can you further speed up a reaction?
A
by adding more substrate or enzyme (increasing the concentration)
