the energy of the
products must be less
than that of the
substrates
an initial boost of energy is needed to kick start
the reaction (activation energy)
structure
active site
enzyme substrate complex
substrate fits into the active site and is held by bonds that
temporarily form between certain amino acids
lock and key model
the shape of the substrate exactly fits
the active site of the enzyme
induced fit
the enzyme is flexible and can
mould itself around the substrate
as it changes shape the enzyme puts strain on the substrate molecule, this
strain distorts a particular bond which lowers the activation energy needed to
break the bond
modified version of lock and key
temperature
a rise in temp increases the kinetic
energy of molecules so they move
more rapidly ad collide more often
so the temp increases the rate of reactiom
at a certain temperature the enzyme is so disrupted so it denatures
pH
a change in pH alters the
charges on the amino acids
that make up the active site
the substrate can no longer become attached to
the active site and so the enzyme substrate
complex cannot be formed
the bonds that maintain the tertiary structure
break and so the enzyme changes shape
the enzymes active site is
now different and the enzyme
therefore denatured