Lesson 3.3 - Environmental Impacts on Enzyme Function 𖦹⋆｡°✩ Flashcards
what can a change to the molecular structure of an enzyme result in
may result in a loss of enzyme function
what is the shape of enzymes
enzymes have unique 3D shapes known as the conformational shape/tertiary structure
what is denaturation
changes in the conformational shape of the enzyme
what can lead to denaturation
༻ changes in environmental temperature
༻ changes in environmental pH
what happens when an enzyme is denatured
the catalytic ability of the enzyme is lost or severely decreased. denaturation is usually irreversible
in some cases, denaturation is reversible. what happens in this case
the enzyme will regain catalytic activity
what can affect the efficiency of enzyme activity and reaction rates
༻ environmental temperature
༻ environmental pH
༻ concentration for substrates and products
༻ enzyme concentration
what are optimum temperatures
range in which enzyme-mediated reactions occur the fastest
when do reaction rates change with regards to temperature
reaction rates change when optimum temperatures aren’t maintained
what happens when there is an environmental increase in temperature
༻ initial increase in reaction rates
༻ increased speed of molecular movement
༻ increased frequency of enzyme-substrate collisions
what happens when temperatures increase outside of the optimum range
temperature increase outside of optimum range results in enzyme denaturation
what happens when there is an environmental decrease in temperature
༻ slowed down reaction rate
༻ decreased frequency of enzyme-reaction collisions
༻ does not disrupt enzyme structure, no denaturation
what does pH measure
the concentration of hydrogen ions in solution measured on a logarithmic scale
what do small pH changes equal
small changes in PH values equate to large shirts in hydrogen ion concentrations
what is optimum pH
the range in which enzyme-mediated reactions occur the fastest
what happens when you change the pH outside of the optimum range
enzyme activity will slow/stop
༻ enzyme denaturation can occur as a result of increases/decreases outside of optimum
what can changes in hydrogen ion concentration disrupt
can disrupt hydrogen bond interactions that help maintain enzyme structure
how can concentration of substrates and products affect reaction rate
༻ initial increase in substrate concentration increases increase reaction rate because more substrates mean more opportunity to collide with enzymes
༻ increased product concentration decreases opportunity for substrate addition because matter takes up space, so more product in an area means a lower chance of enzyme substrate collisions = slower reaction rate
what does substrate saturation result in
results in no further increase in rate; reaction rate will remain constant if saturation levels are maintained
how does a change in enzyme concentration impact reaction rate
༻ less enzyme = slower reaction rate, less opportunity for substrates to collide with active sites
༻ more enzyme = faster reaction rate, more opportunity for substrates to collide with active sites
what do competitive inhibitors bind to
the active site
what are competitive inhibitors
molecules that can bind reversibly/irreversibly to the active site of the enzyme
what do competitive inhibitors do
competes with the normal substrate for the enzyme’s active site
what happens if the inhibitor concentrations exceed substrate concentrations
reactions are slowed
what happens if inhibitor concentrations are significantly lower than substrate concentrations
reactions can proceed normally
what happens if inhibitor binding is irreversible
enzyme function will be prevented
what happens if inhibitor binds reversibly
enzyme can regain function once inhibitor detaches
can molecules only bind to the enzyme’s active site
no, enzymes have regions other than the active site to which molecules can bind
what are these alternate sites called
allosteric sites
what are noncompetitive inhibitors
༻ do not bind to active site, bind to allosteric site
what does binding to the allosteric site cause
binding causes conformational shape change and prevents enzyme function because the active site is no longer available
what can increasing substrate NOT do
cannot prevent effects of noncompetitive inhibitor binding
