FACTORS AFFECTING ENZYME ACTS Flashcards
optimum temperature for most human enzymes
35 and 40°C
the plot of initial reaction velocity (vo) against substrate concentration is hyperbolic
or similar in shape to that of the oxygen-dissociation curve of myoglobin
Hyperbolic shape of the enzyme kinetics curve
Human enzymes start to denature at what temperature?
above 40°C
The rate of an enzyme-catalyzed reaction increases with substrate concentration until a maximal velocity (Vmax)
is reached
Maximal velocity
subclasses of pH
Effect of pH on the ionization of the active site
Effect of pH on enzyme denaturation
The pH optimum varies for different enzymes
2 TYPES OF Substrate concentration
Maximal velocity
Hyperbolic shape of the enzyme kinetics curve
The concentration of H+ affects reaction velocity
Effect of pH on the ionization of the active site
FACTORS AFFECTING ENZYMATIC ACTIVITY
A. Substrate concentration
B. Temperature
C. pH
D. Enzyme concentration
Extremes of pH can also lead to denaturation of the enzyme, because the structure of the catalytically active protein molecule depends on the ionic character of the amino acid side chains
Effect of pH on enzyme denaturation
do not follow Michaelis-Menten kinetics and show a sigmoidal curve that is similar in shape to the oxygen dissociation curve of hemoglobin
allosteric enzymes
The pH at which maximal enzyme activity is achieved is different for different enzymes, and often reflects optimum pH
The pH optimum varies for different enzymes
subclass of temperature
Increase of velocity with temperature
Decrease of velocity with higher temperature
The reaction velocity increases with temperature until a peak/maximum velocity is reached
Increase of velocity with temperature
This increase is the result of the increased number of molecules having sufficient energy to pass over the energy barrier and form the products of the reaction
Increase of velocity with temperature
temperature at which an enzyme exhibits maximum activity
Optimum temperature
