Lec 7 Kinetics Flashcards
k is the blank
rate constant
enzymes speed up attainment of equilibrium by influencing blank
k
linear portion of equilibrium curve is what we use to determine blank
rate
enzyme assay when product yield is measured throughout entire reaction
continuous assay
assay where individual time points are taken
sampled assays
assay where two metabolic reactions that share a common intermediate … product of first is substrate of the second
coupled assay
these can enhance sensitivity, and facilitate data collection during assay
synthetic substrate
enzyme is saturated with substrate at blank
Vmax
study of how enzymes influence the rates of change
enzyme kinetics
Km =
[S] at 1/2 Vmax (Affinity of enzyme for substrate)
Km and Vmax are part of this model
Michaelis menten
michaelis menten model is a blank
square hyperbola
Km does not equal
Vmax / 2 because it is the substrate concentration at 1/2 Vmax
an enzyme does not have to obey michaelis menten and can have a blank
Km
an enzyme that acts on more than one substrate it will usually have a different blank for each
Km
low Km means blank affinity of E for S
high
high Km means blank affinity of the E for S
low
a good way to tell isozymes apart is to look at each of their….
Km’s
low affinity (high Km) may mean that the enzyme isnt even ….
catalyzing the reaction
hexokinase and glucokinase are blank
isozymes
glucokinase is found mostly in the blank and blank
liver/beta cells of pancreas
hexokinase as a blank affinity for glucose than glucokinase
higher
hexokinase is present in blank
most tissues including liver
glucokinase responds when the levels of glucose are blank
high
hexokinase functions more during blank levels of glucose
normal
inhibitors work in a variety of ways and differ in terms of their blank
specificity
general inhibitors like heavy metals inactivate enzymes blank and blank
irreversibly, non specifically
specific enzyme inhibitors are useful in medicine because they can mimic the blank to target enzyme
substrate
these bind at the active center and rom a permanent covalent bond to the enzyme
irreverisble inhibitors
two types of reversible inhibitors
competitive, non competitive
competitive inhibitors bind to the blank center by non covalent bonds
active
noncompetitive inhibitors do not bind to blank
active site
competitive inhibitors are influenced by amount of blank but blank are not
substrate, noncompetitive
competitive inhibitor blank Vmax and blank Km
does not change, increases
noncompetitive inhibitor blank Vmax and blank Km
decreases, doesnt change
converting hyperbolic function of michaelis menten model into linear
lineweaver burk
competitive makes a blank lineweaver burk plot
x intercept change
noncompetitive lineweaver burk plot changes blank
y intercept
an enzyme who’s activity is influenced by multiple variables
allosteric
hemoglobin is not an enzyme but has blank properties
allosteric
enzymes regulated by allosteric effects always have more than one subunit and more than one center….aka
quaternary structure
enzyme that adds phosphate onto a side chain
kinase
enzyme that breaks off a phosphate group
phosphatase
adding a phosphate to something like serine or threonine would make it look more like blank because of negative charge
aspartic acid/glutamic acid
active digestive proteases cannot be synthesized inside cells because they would blank the cells that made them
damage
proteases are secreted as inactive precursors… aka
zymogens
zymogens are blank in the gut
activated
enteropeptidase is synthesized in cells lining the blank and secreted directly…. even though it is an active protease it is no danger to cells that secrete it because it has such a blank
duodenum, limited specificity
kinetic studies amount of product formed in amount of time formula
deltaP/deltaT = k[S]
