What are the six classes of enzymes that we learned? - answer✔1) oxidoreductases
2) transferases
3) hydrolases
4) lyases
5) isomerases
6) ligases
What is competitive inhibition of enzyme? How to overcome competitive inhibition? -
answer✔A competitive inhibitor I binds to E and competes with S for the active site. This lowers
the apparent affinity of E for S (and raises apparent Km).
Inhibition can be overcome by adding more S
What are the 3 characteristics that distinguish living creatures from inanimate objects? -
answer✔They are chemically complex and highly organized. They interact and use energy
(nutrients) from the environment and export end products of metabolism (like CO2 exhale).
THey have the capacity to precisely self-replicate and self-assemble.
Transfer of electrons (hydride ions or H atoms) - answer✔oxidoreductases
Group transfer reactions - answer✔Transferases
Hydrolysis reactions - answer✔Hydrolases
Remove groups, leaving double bonds, or conversely add groups to double bonds -
answer✔Lyases
Transfer of groups within molecules; yield isomeric forms - answer✔Isomerases
What does the competitive inhibition change? Km or Vmax? - answer✔Vmax is not affected
The apparent Km is increased by the factor α
Formation of C-C, C-S, C-O and C-N bonds by condensation - answer✔Ligases
How does a competitive inhibition change the hyperbolic rate-substrate curve and the double-
reciprocal curve, respectively? - answer✔Competitive inhibition changes the hyperbolic rate-
substrate curve by increasing the Km and making the curve more linear at the start.
Competitive inhibition changes the double-reciprocal curve by increasing the angle of the line
from the x-axis
What do "catalytic residues" do? - answer✔Catalytic residues may make covalent bonds with
the substrate or transition state intermediate, but these are always temporary
A site on an enzyme where substrates bind and undergo chemical reaction - answer✔active site
What are functional groups? - answer✔the components of organic molecules that are most
commonly involved in chemical reactions
How do Motrin (Ibuprofen) and Naprosen reduce pain and inflammation? What enzyme do
they bind? - answer✔Arachidonic acid (AA) is an unsaturated C20 fatty acid that is converted
(by adding 2 molecules of O2) into prostaglandins that mediate pain and inflammation.
The enzyme that catalyze this reactions is Cyclo-oxygenase (COX).
Motrin and naprosen are competitive inhibitors of COX.
Is a substance whose shape mimics that of a transition state
Can be used to uncover a catalytic mechanism
Can sometimes act as enzyme inhibitors - answer✔transition state analog
Proteins can be classified by shape, what are the 2 types? What are their properties? -
answer✔1) globular proteins: soluble and spherical
2) fibrous proteins: insoluble and rod-like
What are the four mechanisms of enzymatic catalysis that we learned? - answer✔-Positioning
of substrate(s)
-Proton transfer (acid-base catalysis)
-Covalent catalysis (bond cleavage/formation with the enzyme)
-Metal ion catalysis (ionic interactions, oxidation/reduction)
What is uncompetitive inhibition of enzyme? - answer✔Binds to ES (it may distort the active
site or otherwise prevent conversion of ES to E + P).
If I mention the name of one amino acid, do you know which category it belongs to and its
three-letter and one-letter abbreviation? Make sure you are able to tell. Also know the amino
acid structures and properties. (Be able to recognize the amino acid if you see the structure or
its properties). - answer✔
What are the examples of acid-base catalysis and covalent catalysis, respectively? -
answer✔acid-base catalysis:
-Ribonuclease A
-Chymotrypsin
covalent catalysis
What does the uncompetitive inhibition change? Km or Vmax? - answer✔ESI complex is non-
productive so Vmax is lowered.
The ES reduction increases the E-S affinity (decreases Km).
What are the general characters of red blood cells? Why is carbonic anhydrase important? -
answer✔1) Are "bags of the protein hemoglobin" plus the enzyme "carbonic anhydrase*" (and
many other proteins)
2) Contains NO nucleus and therefore can not divide
3) Are made in the bone marrow from a precursor cell
Live in the blood for 120 d when they are taken up by the macrophages in the
"reticuloendothelial system" (or "mononuclear phagocytic system", which includes spleen,
liver, bone marrow, lymph nodes).
4) Unload the O2 from hemoglobin in capillaries of all tissues
How does an uncompetitive inhibition change the hyperbolic rate-substrate curve and the
double-reciprocal curve, respectively? - answer✔Uncompetitve inhibition changes the
hyperbolic rate-substrate curve by decreasing Km and lowering the curve all together.
Uncompetitive inhibitors affect the double-reciprocal curve by decreasing Vmax, so the line
shifts down the y-axis
A non-protein chemical compound or metallic ion that is required for a protein's biological
activity to happen. - answer✔cofactor
Cofactors can be classified as either inorganic ions or complex organic molecules called _____,
the latter of which is mostly derived from vitamins and other organic essential nutrients in
small amounts. - answer✔coenzymes
A coenzyme that is tightly or even covalently bound is termed a ______ - answer✔prosthetic
group
What is protein purification? Why is it important? What do you consider (in general) before you
purify your protein? - answer✔Purification of a protein is necessary in order to
-determine its amino acid sequence
-determine its three-dimensional structure
-characterize it kinetically
What is the general structure and properties of NAD+? Where does reduction-oxidation occur
and where binds to the enzyme? - answer✔-A two-electron oxidizing agent
-Used in many redox reactions in biochemistry.
-Can be reduced to NADH
-Contains two nucleotides, one is AMP (adenosine monophosphate)
Nicotinamide ring is where reduction-oxidation occurs.
AMP is where NAD+ binds to the enzyme
What is the general method to do protein sequencing? - answer✔1) Determine which amino
acids are present (amino acid analysis)
2) Determine the sequence of smaller peptide fragments (most proteins > 100 a.a., usually
several hundred)
4|Page
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 Brightstars. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $11.49. You're not tied to anything after your purchase.
