Enzyme Kinetics (w10)

Question 1

What is a catalyst and what does it provide ?

Answer 1

Catalyst: provides an alternative pathway for the reaction in which the rate-determining step has a lower Gibbs activation energy than that of the non-catalysed reaction

Question 2

What happens to a reaction at a given temperature ?

Answer 2

At a given temperature, the rate constant is greater for the catalysed reaction, so the reaction is faster

Question 3

What happens when a reaction isn’t catalysed, what is their transition state ?

Answer 3

Non-catalysed reaction proceeds through a single transition state, whereas the mechanism for the catalysed reaction involves the formation of an intermediate

Question 4

What are enzymes ?

Answer 4

Enzymes: protein molecules, catalyse a specific reaction, unchanged by the reactions they catalyse

Question 5

What is the function of enzymes ?

Answer 5

Enzymes catalyse a wide range of reactions in biochemical systems
(human body dilute solution at 37 °C). Without the presence of enzymes, the reactions would take place much too slowly to sustain life.

Question 6

How do enzymes work as catalysts ?

Answer 6

They provide an alternative pathway for the reaction in which the rate-determining step has a lower Gibbs activation energy than that of the non-catalysed reaction

Question 7

In enzyme catalysed reactions which step is reversible and which is irreversible ?

Answer 7

The first step is reversible
Second step is irreversible