lecture 2 COPY Flashcards
true or false, all energy is equal
false
example of high quality energy?
potential energy, chemical energy
example of low quality energy?
heat, entropy
what do living organisms do with energy?
convert high quality into low quality
second law of thermodynamics?
Second Law of Thermodynamics: Entropy plays a crucial role in the second law, which states that in any spontaneous process, the total entropy of an isolated system always increases.
what does the quality of energy depend on?
how much of it is free
what is enthalpy?
total energy (usable and unusable)
what is entropy?
measure of disorder
formula for G?
G=H-TS
what determines whether a process occurs spontaneously?
change in free energy (negative delta G is spontaneous)
what do we mean by the standardization of free energy values?
measured under the same conditions:
-T=298K
-P=1atm
-pH=7
-concentration: 1M
true or false, standard free energies are additive
true
what do we mean by cells capture the free energy released by ATP hydrolysis to create order?
referring to energy coupling. a process that is spontaneous will increase entropy, and the cell will couple this process to a non-spontaneous process, therefore the energy released by the spontaneous reaction will release energy that can then be used (when that energy is used the entropy decreases, which creates order
what is the link between protein folding and ATP
ATP can induce strain in protein structures, which changes the structure of the protein. ATP binding/hydrolysis can distort the 3D structure of proteins
what is the link between the way a protein is folded and free energy? why does this occur?
-folded in a way to minimize free energy
-Systems with lower free energy are more stable and less likely to change spontaneously.
what is reduction?
gaining an electron
what is oxidation?
losing an electron
what do redox reactions do?
-movement of an electron
-These reactions often release energy because electrons move from high-energy states (e.g., in reduced molecules like glucose) to lower-energy states (e.g., oxygen).
what do metabolic enzymes do?
oxidize fuels (which creates energy)
what is the principle electron acceptor in metabolic redox reactions?
NAD+
TRUE OR FALSE, the reductions of NAD+ is spontaneous
true
what does GAPDH do?
brings NAD+ in position to be reduced
when is FAD used?
when the availabe free energy could not reduce NAD+
does the cell harvest more energy from the reduction of NAD+ or the reductioin of FAD?
NAD+
which process does the cell harvest more energy from, ATP hydrolysis or electron acceptance?
electron acceptance
how does the reduction of NAD+ produce energy if the delta G is positive?
Stores electrons (as NADH) to be used in the ETC to produce ATP
the reduction of NAD+ requires energy, but in the long run it will produce ATP through the ETC
whats the Kb constant?
constant that relates kinetic energy of particles with the temperature
what does KbT=0.6kcal/mol refer to
its the baseline amount of energy protein will import wehn bumps into protein next to it at physiological conditions
whats the name of the movement of molecules?
brownian motion
what is the characteristic diffusion coefficient (D)?
characteristic of a molecules diffusion capacity
what is diffusion caused by?
motion caused by collisions
do smaller or larger molecules have a larger D
smaller molecules
true or false, brownian motion is random
true
what are the 3 main types of energies?
-chemical
-mechanical
-electromagnetic
whats the magnitude of cellular forces?
cellular forces are measured in pN to nN
how much is a KbT for the cell?
4.1pN/nM
what exactly is a KbT?
kBT is the thermal energy of a system at a given temperature
what includes electromagnetic energies?
-photons absorbed and emitted
-electrostatic potentials
what do cells do with photons
either absorb or produce them
formula to find how much energy is in photons
E=h(planck’s constant)x(frequency in Hz)
true or false, the surfaces of proteins contain many charged particles
true
true or false, it is easy to calculate strength of non covalent bonds
false
if non covalent bonds holding together are stronger than thermal energy, how do they come apart?
-collisions can break bonds
-1 in 20 collisions break hydrogen bonds
-the energy of a molecule flunctuates
-ex; if two water molecules coming at you from same direction, their energies align and collision is greater
we need to make it over the transition state
how do covalent bonds break?
-much harder
-collision breaks covalent bond every septillion years
-chemical reactions usually break them
whats particular about thermal energy?
This is a constant energy scale that remains the same regardless of the length scale.
why does the cell need to balance all energy types?
cells operate in a regime where thermal energy, chemical bond energy, and mechanical energies are comparable. This balance is critical for efficient molecular processes.
why do we compare ATP hydrolysis to a 20 dollar bank note?
-big enough to do something with
-small enough to avoid too much waste
