Verified Solutions
Which of the following is true regarding heparin? - Answer -it is used clinically as an
anticoagulant
-it simultaneously binds to antithrombin and the target of antithrombin
-it is a sulfated polysaccharide
-it is an allosteric activator of antithrombin
If an enzyme-catalyzed reaction has a velocity of 2 mM/min and a Vmax of 10 mM/min
when the substrate concentration is 0.5 mM, what is the Km? - Answer 2 mM
How are the kinetics of an enzyme-catalyzed reaction affected by a purely
noncompetitive inhibitor? - Answer Vmax decreased, KM unchanged
If a Lineweaver-Burk plot gave a line with an equation of y = 0.490 x + 0.059, what is the
velocity at a substrate concentration of 5 mM? The original units for substrate were in
mM and velocity in mM/s. - Answer 6.37 mM/s
Which of the following properly expresses the Michaelis-Menten equation? - Answer vo
= Vmax [S] / (Km + [S])
How is an enzyme-catalyzed reaction affected by the addition of more enzyme? -
Answer velocity will increase
Which of the following is true regarding transition state analogs? - Answer -they are
competitive inhibitors
-they bind to an active site with much higher affinity than most inhibitors
, -they are much more stable than the transition state
-their affinity for an enzyme is often much greater that the substrate
A Lineweaver-Burk plot is a _____. - Answer double reciprocal plot
If a Lineweaver-Burk plot was made for an enzyme-catalyzed reaction, both with and
without a competitive inhibitor present, what difference would be seen? - Answer the
slope would be less for the inhibited reaction
A plot of velocity versus substrate concentration for a simple enzyme-catalyzed reaction
produces a _____. This indicates that at some point, the enzyme is _____. - Answer
hyperbolic curve; saturated with substrate
An inhibitor that binds to the active site only in the absence of the substrate and in a
reversible fashion is a(n) _____. - Answer competitive inhibitor
How are the kinetics of an enzyme-catalyzed reaction affected by a competitive
inhibitor? - Answer Vmax unchanged, Km increased
An extremely efficient enzyme has a _____ Km and a _____ kcat. - Answer small; large
Some irreversible inhibitors are called _____ because they bind to the active site of the
enzyme and begin the catalytic process, just like a normal substrate. - Answer suicide
substrates
The catalytic constant, or kcat, is also known as the _____. - Answer turnover number
When a substrate and enzyme interact, the first chemical species formed is _____. -
Answer enzyme-substrate complex