The document discusses enzymes and their specificity. It explains that enzymes are proteins that catalyze chemical reactions and only work on specific substrates that fit their active site. This allows enzymes to speed up reactions in the body without being used up. Different types of specificity are described, such as absolute specificity where each enzyme only catalyzes one reaction, and stereochemical specificity where enzymes act on specific three-dimensional structures of molecules. The document provides examples of enzymatic roles in digestion, DNA replication, and the liver breaking down toxins.

1. BIOLOGICAL CATALYSTS: ENZYMES
WHY ENZYMES ARE SO
SPECIFIC
Jennilee T. Abrenica
09082018

3. Activity

4. Related Research
•Wadih Ghattas, Virginie Dubosclard,
Arne Wick, Audrey Bendelac, Régis
Guillot, Rémy Ricoux, Jean-Pierre
Mahy. Receptor-Based Artificial
Metalloenzymes on Living Human
Cells. Journal of the American
Chemical Society, 2018

5. Related Research
• Artificial enzymes perform reactions on
living cells
• Date:July 26, 2018
• Source:American Chemical Society
• Summary: Researchers have designed
artificial enzymes that sit on the surfaces of
living cells and drive reactions that could
someday target drug therapies to specific
organs.

6. •Metalloenzymes are a class of
enzymes that contain a metal ion,
such as zinc, iron or copper. The metal
ion helps the enzyme speed up, or
"catalyze," chemical reactions that
would otherwise occur very slowly or
not at all.

7. •Scientists would ultimately like to
develop a method to produce
therapeutic drugs only at the sites of
specific cells or organs of the human
body, which could reduce side effects,
and enzymes could help them reach
that goal.

8. • Wadih Ghattas, Jean-Pierre Mahy and their
colleagues set their sights on engineering
an artificial enzyme that could catalyze a
useful reaction, called the Diels-Alder
reaction, right on the surfaces of living
cells. Chemists use this reaction to
synthesize drugs, agrochemicals and many
other molecules.

9. How?
• To make their artificial enzyme, the
researchers began with a protein called the
A2A adenosine receptor, which is naturally
present on the surfaces of some cells in the
body. They modified a molecule that binds
to this receptor with a copper-containing
chemical group that catalyzes the Diels-
Alder reaction.

10. • When the researchers placed the resulting
compound in a culture dish containing living
human cells, it attached to the
A2A adenosine receptors on the cells,
forming an artificial enzyme. This enzyme
catalyzed the Diels-Alder reaction with an
up to 50 percent yield.

11. Diels–Alder reaction
• The Diels–Alder reaction is the reaction between a
conjugated diene and an alkene (dienophile) to form
unsaturated six-membered rings. Since the reaction
involves the formation of a cyclic product via a cyclic
transition state, it is also referred to as a "cycloaddition".
The Diels–Alder reaction is an electrocyclic reaction,
which involves [4+2]-cycloaddition of 4 π-electrons of the
conjugated diene and 2 π-electrons of the dienophile (an
alkene or alkyne). The reaction involves the formation of
new σ-bonds, which are energetically more stable than
the π-bonds. This reaction has great synthetic
importance and was discovered by two German
chemists, Otto Diels and Kurt Alder in 1928. They were
awarded the Nobel Prize in 1950

12. •The researchers say that in the future,
artificial enzymes might be designed
that bind to proteins found only on
specific cell types, for example,
cancer cells. Then, the enzyme could
convert an inactive compound into a
drug to selectively kill those cells.

15. • Retrieved from:
https://www.google.com.ph/search?biw=1366&bih=613&tbm=isch&sa=1&ei=uWiKWe_McOZ8QWM7pjICQ&q=enzymes+&oq=enzymes+&gs_l=img.3..0i19
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16. The Basics
• Enzymes help speed up chemical
reactions in the human body.
• They bind to molecules and alter them in
specific ways.
• They are essential for respiration, digesting
food, muscle and nerve function, among
thousands of other roles.

17. The Basics
• Enzymes are built of proteins folded into
complicated shapes; they are present
throughout the body
• The chemical reactions that keep us alive -
our metabolism - rely on the work that
enzymes carry out

18. The Basics
• Enzymes speed up (catalyze) chemical
reactions; in some cases, enzymes can
make a chemical reaction millions of times
faster than it would have been without it
without being consumed in the process.

19. The Basics
•A substrate binds to the active
site of an enzyme and is
converted into products. Once the
products leave the active site, the
enzyme is ready to attach to a new
substrate and repeat the process.

21. What do enzymes do?

23. What do enzymes do?
•The digestive system - enzymes
help the body break down larger
complex molecules into smaller
molecules, such as glucose, so
that the body can use them as
fuel.

25. What do enzymes do?
•DNA replication - each cell in your
body contains DNA. Each time a cell
divides, that DNA needs to be copied.
Enzymes help in this process by
unwinding the DNA coils and copying
the information.

27. What do enzymes do?
•Liver enzymes - the liver breaks
down toxins in the body. To do this,
it uses a range of enzymes.

28. Enzymatic Activity

30. Why enzymes are specific?
• One enzyme - one job
• Enzymes are specific. Only molecules with
the correct shape can fit into the enzyme.
Just like only one key can open a lock, only
one type of enzyme can speed up a
specific reaction. This is called the lock
and key model.

31. • Absolute specificity - the enzyme will catalyze
only one reaction.
• Group specificity - the enzyme will act only on
molecules that have specific functional groups,
such as amino, phosphate and methyl groups.
• Linkage specificity - the enzyme will act on a
particular type of chemical bond regardless of the
rest of the molecular structure.
• Stereochemical specificity - the enzyme will act
on a particular steric or optical isomer.

33. • Absolute specificity - the enzyme will catalyze
only one reaction.
• Group specificity - the enzyme will act only on
molecules that have specific functional groups,
such as amino, phosphate and methyl groups.
• Linkage specificity - the enzyme will act on a
particular type of chemical bond regardless of the
rest of the molecular structure.
• Stereochemical specificity - the enzyme will act
on a particular steric or optical isomer.

35. • Absolute specificity - the enzyme will catalyze
only one reaction.
• Group specificity - the enzyme will act only on
molecules that have specific functional groups,
such as amino, phosphate and methyl groups.
• Linkage specificity - the enzyme will act on a
particular type of chemical bond regardless of the
rest of the molecular structure.
• Stereochemical specificity - the enzyme will act
on a particular steric or optical isomer.

40. References
• American Chemical Society. "Artificial enzymes perform
reactions on living cells." ScienceDaily. ScienceDaily, 26
July 2018.
<www.sciencedaily.com/releases/2018/07/180726085732.
htm>. Retrieved from
https://www.sciencedaily.com/releases/2018/07/18072608
5732.htm
• https://www.sigmaaldrich.com/technical-
documents/articles/chemistry/diels-alder-reaction.html