Enzyme Activity Flashcards
What is activation energy?
The minimum energy the substrates must have to allow the reaction to occur
What happens when the temperature is increased in an enzyme catalysed reaction?
The number of molecules with the activation energy is increased.
What happens when the concentration of the substrates is increased?
Increases the chance of molecular collisions so rate of reaction increases
What is the function of an enzyme?
A biological catalyst that increases the rate of reaction by lowering the activation energy.
List 3 properties of an enzyme
Highly-specific
Unchanged after the reaction
Do not affect reaction equilibrium
Increase rate of reaction
What is an active site?
The area of an enzyme where substrates bind and the chemical reaction occurs.
How is an enzyme able to be specific?
The active site will be a complementary shape to a specific substrate
What is the optimum temperature for a human enzyme?
37 degrees Centigrade
What is the optimum pH for a human enzyme?
Varies depending on where it works in the body
What does the Michaelis- Menten Model propose?
A complex between the substrate and enzyme is a necessary intermediate
What is the definition of Vmax?
The maximum rate of a reaction when all enzyme active sites are saturated
What is the definition of Km?
The substrate concentration that gives half the maximum velocity of a reaction
What does Km give a measure of?
The affinity of an enzyme for its substate
What is an enzyme inhibitor?
Molecules that slow down or prevent an enzyme reaction
Describe the actions of a competitive enzyme inhibitor? (+ effect on Km and Vmax)
A molecule with a similar shape to the substate binds to the active site of an enzyme instead of the substate. There is no effect on the Vmax but the Km increases.
