Enzymes Flashcards
Turn over number?
The number of molecule substrates converted to product per enzyme molecule per second
6 classes of enzymes
- Oxidoreductase
- Transferases
- Hydrolases
- Lyases
- Isomerases
- Ligases
The rate of reaction is dependent on:
The amount of molecules that have sufficient energy to pass through the transition state
What are the factors affecting the active site?
Geometric stabilization of the transition state. Contribute with other chemical factors that increase probability, e.g. Provide protons as a acid-base catalysis
What are factors that affect reaction velocity?
Substrate concentration, temperature and pH
Velocity of reaction is usually given in?
Mikromol per minute
What is the difference between the curve of Michaelis-Menten kinetics and allosteric enzymes?
MM is hyperbolic, allosteric is sigmoid
What is the MM equation?
Vo = Vmax * [S]
Km + [S]
How do you find Km?
(k-1 + k2)/k1
What assumptions are made wham we use the MM equation?
That the concentration of substrate is much greater than the enzyme, steady stat (concentration of ES does not change) and initial velocity (the rate of reaction is measured as the enzyme and substrate is mixed)
Km is dependent on and not dependent on?
Dependent on type of enzyme and substrate, and not dependent on concentration of enzyme
What is the Km numerically equal to?
Substrate concentration the reaction velocity is half of maximum (1/2vmax)
The rate of reaction is —- to the enzyme concentration at all substrate concentration
Directly proportional
When [s] is much less then Km what is the velocity?
Approximately proportional to the substrate concentration
When is the rate of the reaction a first order reaction?
When the [s] is much less then the Km
