AL - Kinetics 2 Flashcards
1
Q
What are 3 factors that affect rate of reaction?
A
- Concentration (first or second order)
- Kinetic Energy (temperature)
- Orientation
2
Q
How many transition states and intermediates are present in SN1?
A
Transition states: 2
Intermediates: 1
3
Q
How many transition states and intermediates are present in SN2?
A
Transition states: 1
Intermediates: 0
4
Q
How does increasing temperature affect collisions?
A
- Increases the movement of molecules in the system, so the number of collisions increases
- Increases the overall kinetic energy in the system, so a greater proportion of molecules will have enough energy to interact
5
Q
What links rate constant and temperature?
A
k=Ae⁻ᴱᵃ/ᴿᵀ
6
Q
What 2 things increase the value of k?
A
- Increase in temperature
- Decrease in activation energy
7
Q
What are 3 methods to decrease activation energy?
A
- Change in solvent (polarity)
- Chirality (steric hindrance)
- Catalysts
8
Q
How do enzymes lower the activation energy? (3)
A
- Bring chemical groups together in the correct orientation
- Create a more favourable environment for the reaction
- Stabilise the transition state
9
Q
What 3 assumptions can be made relating to the michaelis menten model?
A
- Since [S]»[E] we can assume that free [S] doesn’t change and [ES] doesn’t change
- Ignore the backward reaction from [P]->[S] since the concentration of [P] is very low
- Assume that product release from [EP] is rapid
10
Q
What is Vmax?
A
[E]kcat
Theoretical maximum reaction rate at the enzyme concentration
11
Q
What is Kcat?
A
The catalytic rate constant
- Number of substrate molecules converted to product per enzyme per unit of time
