Lecture 1 - The mechanisms of energy transduction Flashcards
(50 cards)
what plants do in terms of energy (high to low qual, low to high qual, etc.) ? (2)
1) transform high qual energy from sun into high qual energy under chemical form (cellulose fibers)
2) transform high qual. energy to low qual energy
G = H - TS . meaning of G
Free energy or available energy (that can be used)
G = H - TS . meaning of H
Enthalpy, total energy
G = H - TS . S meaning (and TS meaning)
S = entropy (measure of disorder). TS = unavailable energy
high qual vs low qual energy (order vs disorder) from a molecular pov (a proper def. for order)
Low qual energy/disorder : molecule can adopt a lot of different microstates
high qual energy/order : molecule can not adopt a lot of different microstates
A system usually wants to adopt many different __________
microstates
Gibb’s definition of entropy
number of different microstates a system can adopt
In Joule’s experiment, why do we say that high qual energy becomes low qual energy
energy of atoms in the mass all going in the same direction is converted to energy of water molecules (kinetic energy) going in all directions (random energy/heat)
what determines if a process occurs spontaneously (use formula and different forms)
if ▲G < 0 ( which happens because ▲G = ▲H - T▲S and ▲ increases - ▲S > 0 - for a spontaneous process)
what is done to reactions’ ▲G to simplify calculations
free energy values of reactions are standardized (symbol ▲G0’)
possible utility (what rule) of standardizing free energies of reactions when we want to calculate free energy of A->C
Standard free energies are additive. Add ▲G of A-> B and ▲G of B->C
reaction’s energy diagram description
reactants level, transition state (has a ▲G), products level (can be lower or higher)
what catalysts do with regard to ▲G
they lower the height of the ▲G reactants must acquire to reach the transition state
2 ways for molecules to reach a transition state
1) through an unspontaneous reaction (positive ▲G)
2) through a spontaneous reaction (negative ▲G)
▲G ratio of reaction vs transition state
▲G of the whole reaction is 4 times smaller than ▲G of the transition state
Ludwig Boltzmann’s finding and justification
Energy of a system fluctuates because energy of a molecule fluctuates due to constant collisions of molecules
What the Boltzmann distribution does and tells
describes fluctuation of a system’s energy and probability that a system is at a particular energy level
How to make it over the transition state considering Boltzmann’s findings
Energy of the system must fluctuate above the ▲G of the transition state
What differentiates low rate vs high rate reactions and how + explanation
low rate reaction = low ▲G because this causes the system to have a higher probability of fluctuating to this energy state
All reactions are theoretically reversible but why is it not true practically
some reactions are irreversible because ▲G of reverse reaction is too high (prob of reaching that is too low)
enzymatic reaction : description of enzyme/substrate interactions (type of bond,
non-covalent interactions, substrate is in catalytic site. enzyme-substrate complex.
lock and key mechanism
what triggers release of substrates from an enzyme
random collisions and energy fluctuations
glucose transformation into CO2 and water : positive or negative ▲G, what will this serve for
highly negative ▲G -> production of ATP because ADP + Pi -> ATP has a positive ▲G
what do we say about glucose oxidation reaction and ATP synthesis (condensation) reaction
are coupled reaction
