2. What are Galvanic Cells?
Galvanic cells are an electrochemical cell that converts the
chemical energy of spontaneous redox reactions into electrical
energy
They are named after the scientists Luigi Galvani and Alessandro
Volta and they are used to to supply electrical current through a
redox reaction to the transfer of electrons
3. Galvanic cells use oxidation and reduction reactions in them and
they are used in medicine in a variety of ways ……. oxidation is
catalyzed by cytochrome P450 enzymes and results in the loss of
electrons from the drug (electrons are negatively charged
subatomic particles). The drug is now said to be oxidized and after
phase 1 reactions, the resulting drug metabolite is still often
chemically active
4. An example of an oxidation reaction is the hydroxylation of
amphetamine to 4-hydroxyamphetamine and
norephedrine. Another example is hydroxylation of delta-
9-THC to 11-OH-delta-9-THC
5. Oxidation and reduction reactions, provide cellular energy,
because the flow of electrons between molecules produces
usable energy. Metabolism is the sum of chemical reactions that
occur within each cell to supply energy for important cellular
processes
When we 'burn' glucose for energy, we transfer (by a series of
enzyme-catalyzed reactions) electrons from glucose to molecular
oxygen ( O2), oxidizing the six carbon molecules in glucose to
carbon dioxide and at the same time reducing the oxygen atoms in
O2
to water.
6. The transfer of electrons from glucose to O2 is a thermodynamicallydownhill, energy-
releasingprocess, just like the transfer of electrons from zinc metal to copper ion. And while
you could have used the energy released by the zinc/copper redox reaction to light a small
light bulb, your cells use the energy released by the glucose/oxygenredox process to carry
out a wide variety of energy-requiringactivities
On a global scale, oxidation of the carbons in glucose to CO2
by non-photosyntheticorganisms (like people) and the subsequent reductive synthesisof
glucose from CO2
by plants is what ecologists refer to as the 'carbon cycle'.
In general the more reduced an organic molecule is, the more energyis released when it is
oxidized to CO2
. Going back to our single-carbonexamples, we see that methane, the most reduced
compound, releases the most energy when oxidized to carbon dioxide, while formic acid
releases the least
7. After we break down and oxidize sugar and fat molecules
to obtain energy, we use that energy to build large,
complex molecules (like cholesterol, or DNA) out of small,
simple precursors. Many biosynthetic pathways are
reductive: the carbons in the large biomolecule products
are in a reduced state compared to the small precursors.
Look at the structure of cholesterol compared to that of
acetate, the precursor molecule from which all of its
carbon atoms are derived - you can see that cholesterol is
overall a more reduced molecule.
16. As we put all these
components together,
electrons start to flow from
the negative part to the
positive which will cause
electricity
As Zink atoms lose
electrons they become Zn2
and dissolve in water, and
that is the oxidation process
17. On the other side, the Cu
gains the electrons of the
Zink and that is the reduxion
reaction of the galvanic cell
and this half of the galvanic
cell is called the cathode
18. As the reaction goes on the
cathon goes bigger and
bigger as it gets more ions
and the anode gets smaller
as it loses ions
19. You can notice that there are positive ions accumulated on the left side and
negative ions in the right side, if there were no ion bridge one cell is gonna
gather the positive ions together and the other one would gather the
negative ones perverting further reactions
20. Fortunately we have the salt bridge which is filled with electrolyte which can be
constructed from several components mainly negative and positive ions
21. The positive ions migrate into the solution where the negative ions are
accumulated and migrate into the solution where the positive ions are located
22. Uses of Galvanic Cells
Galvanic cells are used in batteries as the electrons flow from one
chemical reaction to another occurs through an external circuit that
results in the current
And they provide the foundation of generating electric current
spontaneously from a chemical reaction.
So learning all of this galvanic cells are so important and form the shape
of many things we use in our daily lives.