Concept
Statements |
Emphasis
in
your teaching
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General
importance
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| 1.The cell is
the basic unit of life. The free
form of viruses,
virions, are not alive, they are ametabolic.
To replicate a virus must invade and parasitize a cell. |
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| 2.Cells
are bounded systems of interacting chemical reactions.
The rates of these reactions are controlled by catalysts (enzymes and ribozymes). |
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| New. Metabolism is the sum of all of the chemical reactions that occur
within a particularly living system. |
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| 3.Cells
are non-equilibrium systems
that depend upon the continual influx of energy and
the export of entropy. |
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| 4.Living
organisms obey all of the laws of thermodynamics. |
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| 5.When
a molecule is reduced electrons are
added to it. Oxidation is
the opposite, it involves the the removal of electrons. |
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| 6.The
addition of electrons to a molecule increases its free
energy. |
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| 7.Under
the conditions that normally exist within a cell, energy
can be stored by reducing molecules
and released upon their oxidation. |
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| 8.The rate of
a reaction reflects the step in the reaction with the
highest activation energy.
This step is the the rate limiting step. |
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| 9.Catalysts act
to reduce the activation energy of a reaction. |
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| 10.It
is possible to couple, through common intermediates,
reactions that are energetically favorable
with those that are energetically unfavorable, so that
energetically unfavorable reaction occurs to a significant
extent. |
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| 11.The equilibrium
constant of a reaction reflects the
concentration of reactants and products when the
reaction reaches equilibrium.
The equilibrium constant does not provide an estimate
for the time it takes for the reaction to reach equilibrium. |
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| 12.Biological
catalysts are either proteins (enzymes),
RNAs (ribozymes)
or macromolecules complexes (e.g. the ribosome and
the splicesome)
that contain both polypeptides and RNAs. |
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| 13.
The energy of
visible light can be captured by cells using pigments,
associated with proteins, that absorb these wavelengths of
light. |
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| 14.
When light is absorbed by a molecule, an electron moves
into a higher energy state. The electron is said to be excited.
When the electron relaxes this energy can excite an electron
in another molecule, be emitted as a photon (fluorescence)
or transformed into molecular motion (heat). |
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| 15.
An electron transport chain (ETC)
is a series of membrane proteins. |
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| 16.
As an excited electron moves through an electron transport
chain, the components of the electron transport chain
undergo sequential oxidation and reduction. |
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| 17.
As electrons move through an electron transport chain,
H+s are pumped across a membrane, generating
a H+ gradient. |
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| 18. Adenosine
triphosphate (ATP) is a major storage
form of chemical energy within cells. |
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| 19.
ATP can be generated from adenosine
diphosphate (ADP) and phosphate as
H+s move through the membrane-protein ATP
synthase, an enzyme. |
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| 20.
The hydrolysis of
ATP into ADP and phosphate can be used to generate ion
gradients across membranes. |
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| 21. A non-equilibrium situation, for example the existence
of a high concentration of protons on one side of a membrane
and a low concentration on the other, provides an opportunity
for cells to capture energy to do metabolic work. |
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