1
st
Exam Biochem 104b, 2007
Question 1
10 points
a)
What is the MaxwellBoltzmann distribution, what does it describe and what
is its significance (use a few short sentences, don’t just write down the equation)?
Answer:
Given an external restraint on the average free energy of a molecular system,
the highest entropy state this system can adopt will be described by the Maxwell
Bolztmann distribution. Since systems always tend towards their maximum entropy
state, we can use the MaxwellBoltzmann distribution to calculate the relative probability
of finding a molecule in a particular state, simply based on that states energy relative to
the energy of all other states.
5 points
b)
What is the shape of the MaxwellBoltzmann distribution?
Answer:
The MaxwellBoltzmann distribution describes the relationship between the
free energy of a molecular state and the probability of adopting that state. The shape of
this function is that of exponential function (e
x
) where lower energy states are more
common and higher energy states are less common.
15 points
c)
You have a protein that can exist in 4 different interconverting
conformations.
Δ
G
unfold
12kcal/mol 15kcal/mol 13kcal/mol 16kcal/mol
From unfolding experiments you know the standard free energy of unfolding for each of
these states (the unfolded state is the same in each case). Calculate the relative
probability of find the protein in state A and state D. (Assume a temperature of 298 deg.
K). Also
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '07
 Miller
 Entropy, 2 %, Gbinding, #TN, 1.68 K, 12kcal

Click to edit the document details