Thermodynamics Flashcards
what is glycolysis?
process where glucose converted to pyruvate
aerobic process
what do we need to understand for thermodynamics?
why do biochemical processes go the way they of and stop where they do
life obeys laws of thermodynamics
what are the two sections in thermodynamics?
the system (easily measured and controlled)
the universe (everything else)
what is a closed boundary?
where only work and energy can cross the boundary into the system
no crossing of physical matter
what is the first law of thermodynamics?
energy can neither be created or destroyed
explain the first law of thermodynamics
energy (U) change of system defined as difference between heat (Q) absorbed by system from surroundings and work (W) done by system on the surroundings
chaining an energy from one state to another
what is the equation for when the system undergoes change?
deltaU = Q-W
u= internal energy of the system
q= heat put into the system
w= work done by the system on the surroundings
delta indicates change
what is meant by the term work?
force times the distance moved
- motion
what are the different forms of work?
gravitational force exerted by one mass on another
expansional force exerted by a gas
tensional force of a muscle fibre
electrical force of charge
what is the enthalpy equation?
H = U + PV
h= enthalpy
u = internal energy
p = pressure
v= volume
how is enthalpy equivalent to heat?
volume changes in most biological reactions are insignificant
difference between internal energy and enthalpy negligible
energy change = enthalpy change
is spontaneity necessary?
2 objects that are brought together
heat spontaneously flows from hot to cold
additional element spontenaity needed
can you predict a reaction direction?
is reaction absorbs or releases heat cannot predict whether reaction will happen
no
what is the second law of thermodynamics?
the total entropy of any isolated thermodynamic system tends to increase over time, approaching maximum value
isolated system
allows no transfer of matter, energy to work across the boundary
what is entropy?
measure of the disorder in the system
explain entropy
orderliness of system related to how likely arrangement is likely to happen by chance
more ways in which can happen by chance, greater the disorder
law of statistics, not absolutes
how do you calculate entropy?
s = kb in w
s= entropy
kb= Boltzmann constant5
w= number of ways
what is Gibbs free energy?
energy provided to environment as heat will create further disorder in environment
what is the free energy equation?
G = H -TS
g= free energy
h= enthalpy
t= temperature
s= entropy
JMol-1
G less than or = 0 means spontaneous
what are coupled reactions?
achieved by coupling extremely favourable reactions to unfavourable reactions
relies of reverse of the unfavourable reaction being slow in cell
living systems take in organised energy
high enthalpy, low entropy
turning this into disorderly heat energy and waste products
low enthalpy, high entropy
what are the standard conditions?
25oC
1 atm
pH 7
