Thermodynamics 2

Question 1

What is the probability of having an energy of potential energy equal to?

Answer 1

e^(-PE/KbT)

Question 2

Are higher energy states more or less probable?

Answer 2

Less probable

Question 3

What is Kb and T in the probability equation?

Answer 3

Kb = Boltzmann constant
T = temperature

Question 4

How do you calculate the kinetic energy for 1 mole?

Answer 4

KE = NA x Kb x T = RT
NA = Avogadro’s constant

Question 5

What do calculations per molecule use and per mole use?

Answer 5

-per molecule = KbT
-per mole = RT

Question 6

What is change in potential energy equal to?

Answer 6

Delta PR = delta H

Question 7

For proteins, is there more ways of being folded or unfolded?

Answer 7

Unfolded

Question 8

Is the reaction that causes a protein to go from folded to unfolded likely and why?

Answer 8

Unlikely - requires lots of favourable collisions with surrounding molecules

Question 9

Is the reaction that causes a protein to go from unfolded to folded likely and why?

Answer 9

Likely - attractive forces tend to bring it back to its folded state

Question 10

Describe the entropy of a protein in its folded and unfolded state

Answer 10

-folded = low entropy
-unfolded = high entropy

Question 11

At low temperatures, are proteins mostly folded or unfolded?

Answer 11

-mostly folded
-few likely folded states
-many unlikely unfolded states

Question 12

At high temperatures, are proteins mostly folded or unfolded?

Answer 12

-mostly unfolded
-many unfolded states, so now only fairly unlikely

Question 13

How do you calculate free energy (G)?

Answer 13

G = H - TS

Question 14

How do you calculate change in free energy (ΔG)?

Answer 14

ΔG = ΔH - TΔS

Question 15

What does free energy of a (macro)state take into account?

Answer 15

-the likelihood of the microstates (PE of microstate is roughly the enthalpy)
-the number of microstates (S = Kb ln(N))