lab quiz 4 Flashcards
how are chemical reactions sped up?
the formation of an enzyme substrate complex which reduces the every required for the specific reaction to occur
enzyme’s specific shapes and structures
conformation
enzymes are primarily
proteins
conformation of an enzyme determines its
function
the enzyme’s _______ is selective, only allowing certain substances to bind
active site
enzyme’s activity is
the rate at which it converts substrate to product
activators
chemicals that bind to an enzyme and increase its activity
inhibitors
chemicals that bind to an enzyme and decrease its activity
cofactors
non-protein chemicals which bind to an enzyme and are essential to its functioning
types of cofactors
metal ions or coenzymes
two common ways of measuring enzyme activity
- determine rate at which substrate is used
- rate at which product is formed
many enzymes absorb or transmit of certain wavelengths, so their change in concentration can be determined by measuring…
rates of color change
catechol oxidase is an
enzyme
catechol is the
substrate
catechol oxidase (enzyme) converts catechol (substrate) into the product:______
benzoquinone
why do plants have catechol oxidase?
helps to protect damaged plants against both bacterial and fungal disease AND predators by producing benzoquinone
how does concentration of substrate affect enzyme activity?
As the concentration of the substrate increases, so does the rate of enzyme activity until saturation is reached
how does concentration of enzyme affect enzyme activity?
increasing enzyme concentration will speed up the reaction, as long as there is substrate available to bind to. Once all of the substrate is bound, the reaction will no longer speed up, since there will be nothing for additional enzymes to bind to.
how does concentration of enzyme affect enzyme activity?
how do changes in pH affect enzyme activity?
there is an optimal pH range, but if you go outside the range (up or down) it will decrease enzyme activity
why do you blank when using a spectrophotometer ?
-This ensures the absorbance measured in the samples is attributed only to the sample material and not the components of the solution the sample is suspended in or the cuvette.
-so that the instrument can zero out these background readings and only report values for the compound of interest
enzymes bind to
substrates
