Limiting Factors Affecting Enzymes: Competitive Inhibitors

Question 1

An enzyme’s activity can be reduced or stopped, temporarily, by a reversible inhibitor
There are two types of reversible inhibitors:
Competitive inhibitors have a

Answer 1

similar shape to that of the substrate molecules and therefore compete with the substrate for the active site

Question 2

Reversible inhibitors can act as

Answer 2

regulators in metabolic pathways

Question 3

Why do metabolic reactions have to be tightly controlled

Answer 3

Metabolic reactions must be very tightly controlled and balanced, so that no single enzyme can ‘run wild’ and continuously and uncontrollably generate more and more of a particular product

Question 4

For competitive inhibitors, countering the increase in inhibitor concentration by increasing the ………….. can increase the rate of reaction once more

and why is this

Answer 4

substrate concentration

more substrate molecules mean they are more likely to collide with enzymes and form enzyme-substrate complexes)

Question 5

While a competitive inhibitor will lower the initial rate of reaction (by occupying some of the available active sites), eventually the same amount of

Answer 5

product will be produced as would have been produced without the competitive inhibitor (the maximal rate is not affected)