STATION 2
GRAPHS TO SHOW THE EFFECTS OF
INHIBITORS ON ENZYME ACTION
NAVIGATE YOUR WAY THOUGH ALL
Inhibitors and Enzyme Action
WJEC GCE BIOLOGY
OF THE ANIMATIONS CLICKING ON
EXPLANATIONS EACH TIME
THEN COMPLETE THE WORKSHEET
Rate of reaction
Inhibitors and Enzyme Action
WJEC GCE BIOLOGY
NORMAL ENZYME REACTION RATE
1
Substrate concentration
NORMAL ENZYME REACTION RATE
Forward
Inhibitors and Enzyme Action
WJEC GCE BIOLOGY
Explaination
Rate of reaction
Inhibitors and Enzyme Action
WJEC GCE BIOLOGY
NORMAL ENZYME REACTION RATE
2
1
Substrate concentration
Forward
NORMAL ENZYME REACTION RATE
Every active site is saturated. The
rate of the reaction is at its
highest.
Inhibitors and Enzyme Action
WJEC GCE BIOLOGY
Close
Explanation
Rate of reaction
Inhibitors and Enzyme Action
WJEC GCE BIOLOGY
NORMAL ENZYME REACTION RATE
2
3
1
Substrate concentration
Forward
NORMAL ENZYME REACTION RATE
Every active site is
saturated, so there is no
increase in the rate of
reaction.
Inhibitors and Enzyme Action
WJEC GCE BIOLOGY
Close
Example
NORMAL ENZYME REACTION RATE
Rate of reaction
Inhibitors and Enzyme Action
WJEC GCE BIOLOGY
2
3
Revise
1
Competitive
Inhibitor
Substrate concentration
COMPETITIVE INHIBITOR REACTION RATE
Rate of reaction
Inhibitors and Enzyme Action
WJEC GCE BIOLOGY
2
Revise
1
Non-competitive
Inhibitor
Substrate concentration
COMPETITIVE INHIBITOR EXAMPLE:
AN IMPORTANT ENZYME IN RESPIRATION IS SUCCINATE
DEHYDROGENASE. ITS SUBSTRATE IS SUCCINATE, WHICH
IS CONVERTED INTO FUMARATE
Succinate
A competitive inhibitor
binds to the enzyme’s
active site, and slows down
the process.
Malonate
Inhibitors and Enzyme Action
Close
WJEC GCE BIOLOGY
Forward
Explanation
Succinate
dehydrogenase
COMPETITIVE INHIBITOR EXAMPLE:
AN IMPORTANT ENZYME IN RESPIRATION IS SUCCINATE
DEHYDROGENASE. ITS SUBSTRATE IS SUCCINATE, WHICH IS
Forward
CONVERTED INTO FUMARATE
Succinate
The substrate will soon find
an active site. The effect of
a competitive inhibitor is to
slow down the process.
Malonate
Inhibitors and Enzyme Action
WJEC GCE BIOLOGY
Close
Explanation
Succinate
dehydrogenase
Rate of reaction
Inhibitors and Enzyme Action
WJEC GCE BIOLOGY
NON COMPETITIVE INHIBITOR
2
1
Re-Revise
Substrate concentration
NON COMPETITIVE EXAMPLE:
COPPER SULPHATE AND CATALASE
Forward
The shape of the active site
changes because the noncompetitive inhibitor has
bound to an allosteric site; so
preventing an enzymesubstrate complex from
forming = less products
formed
Hydrogen
peroxide
Inhibitors and Enzyme Action
WJEC GCE BIOLOGY
Close
Explanation
CuSO4
Catalase
NON COMPETITIVE EXAMPLE:
COPPER SULPHATE AND CATALASE
Forward
Hydrogen
peroxide
The reaction rate cannot
reach the same point
because the noncompetitive inhibitors have
changed the shape of some
of the active sites.
Inhibitors and Enzyme Action
WJEC GCE BIOLOGY
Close
Explanation
CuSO4
Catalase