Temperature Concetration and Inhibitors Flashcards
What 2 effects does increasing temperature have on the energy of a system?
Kinetic effect
- increased motion of molecules
- increased collision between E and S
- increased rate of reaction
Denaturing effect
- increase in temperature breaks weak bonds in the tertiary structure (H-bonds) and new ones are formed creating a new 3D structure
What is the shape of the graph for the rate of denaturation as temperature rises?
negatively exponential
In a substrate concentration graph describe the kinetics and concentrations at a) the exponential stage b) the stationary phase
a) first order kinetics, [S] controls the ROR
b) zero order kinetics, [E] controls the ROR
What is the Michealis-Menten equation?
V= Vmax[S]/Km + [S]
Km = MM constant, Vmax = max initial reaction velocity
What is the Lineweaver-Burk equation and why is it used?
It is the inverse of the Micheal-Menten equation. It is used in the MM graph the plateau is only truly reached at infinity high [S]. It is impossible to carry out an experiment at this level therefore LB is used
How do non-competitive inhibitors work?
They don’t bind to the protein active site, but to an alternative site on the enzyme instead. They change to shape of the enzymes active site so that it can no longer bond to the substrate to change it. Cant be overcome by increasing [S]. Treatment is with dialysis
How do competitive inhibitors work?
They bind reversibly into the AS of the enzyme, physically stopping the substrate from binding. It can be overcome but increasing the [S]
How do irreversible inhibitors work?
They bind irreversibly to a AA side chain near the AS, usually ser or cys. This permanently inactivates the enzyme and stops any future bonding of S.
E.g.:to the enzyme usually by covalent bond
