Enzymes are not as efficient as most catalysts used in organic chemistry, since they
must function at body temperature.
True or False? -Answer False
A biotechnology company has cloned four different forms of the enzyme money
synthetase which catalyzes the reaction:
Garbage + ATP = Money + ADP + Phosphate + H+
The Km and Vmax values of these enzymes for the substrate garbage are as follows:
Enzyme 1; Km = 0.1mmol Vmax = 5.0 mmol/min
Enzyme 2; Km = 0.3 mmol Vmax = 2.0 mmol/min
Enzyme 3; Km = 1.0 mmol Vmax = 5.0 mmol/min
Enzyme 4; Km = 3.0 mmol Vmax = 20.0 mmol/min
Which of the four enzymes is fastest at a saturating ATP concentration and a garbage
concentration of 0.01 mmol/L?
A. Enzyme 1
B. Enzyme 2
C. Enzyme 3
D. Enzyme 4
E. None of the above -Answer A. Enzyme 1
v = (Vmax x [S])/Km + [S]
Enzyme 1
v = 5 x 0.01/0.1 + 0.01
v = 0.05/0.11 = 0.45
Enzyme 2
v = 2 x 0.01/0.3 + 0.01
, v = 0.02/0.31 = 0.06
Enzyme 3
v = 5 x 0.01/1.0 + 0.01
v = 0.05/1.01 = 0.05
Enzyme 4
v = 20 x 0.01/3.0 + 0.01
v = 0.20/3.01 = 0.07
What distinguishes reversible inhibitors from irreversible inhibitors?
A. Reversible inhibitors are not covalently bound to enzymes but irreversible inhibitors
are.
B. There is an equilibrium between bound and unbound reversible inhibitor.
C. There usually is very little reverse reaction for the binding of an irreversible inhibitor.
D. Reversible inhibitors are easier to purify from solutions of enzymes than irreversible
inhibitors.
E. A, B, & C above
F. A and B only -Answer E. A, B, & C above
Enzymes differ from other catalysts in that enzymes:
A. lower the activation energy of the reaction catalyzed.
B. fail to influence the equilibrium point of the reaction.
C. form an activated complex with the reactants.
D. usually display specificity toward a single reactant.
E. are not consumed in the reaction. -Answer D. usually display specificity toward a
single reactant.
What is the estimate of Vmax if the total enzyme concentration in each reaction mixture
is doubled?
Vo = 0.5micromol/min -Answer Vmax is proportional to the enzyme concentration.
Doubling the enzyme concentration will produce a new Vmax of 2 x 0.50 micromol per
minute = 1.00 micromole per minute.
In a first order chemical reaction, the velocity of the reaction is proportional to the
________, while in a zero order reaction, the velocity of the reaction is proportional to the
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Zayla. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $12.99. You're not tied to anything after your purchase.