Phosopholipids in Salty solutions

  • Thread starter Thread starter Krazer101
  • Start date Start date
AI Thread Summary
The discussion revolves around calculating the areal charge density and surface potential of a phospholipid bilayer membrane composed of 90% uncharged lipids and 10% charged lipids in a 100mM NaCl solution at 25 degrees Celsius. The user expresses confusion about how to model the membrane and apply the percentage of charged versus uncharged lipid head groups in their calculations. They consider using concentric spheres to find the potential but are uncertain about how to approach the charge density calculation. The conversation highlights the need for clarity on the application of relevant equations and modeling techniques for this type of membrane system. Understanding these concepts is crucial for accurately determining the membrane's electrochemical properties.
Krazer101
Messages
18
Reaction score
0

Homework Statement


Consider a phospholipid bilayer membrane consisting of a mixture of 90% uncharged lipid and 10% singly charged acid lipid. Assume 68 Angstroms surface area per lipid head groups, and assume further that the charged lipids are uniformly distributed and immobile. The membrane is in contact with an aqueous solution of NaCl at 25 degrees celcius. The salt concentration is 100mM.

a.) Calculate the areal charge density of the membrane

b.) Calculate the surface potential of the membrane


Homework Equations


area density = derivative of charge?
Electric field and potential equations

The Attempt at a Solution



I am totally stuck and have no idea where to begin. I was first wondering what to model the membrane as? Should I model the bilayer as concentric spheres? I believe if I use concentric spheres, I can find the potential. I am unsure about the charge density; I don't quite understand how to use percentage of heads that are charged/not for this.
 
Physics news on Phys.org
Anyone know where to start?
 
Thread 'Confusion regarding a chemical kinetics problem'

Thread 'Confusion regarding a chemical kinetics problem'

TL;DR Summary: cannot find out error in solution proposed. [![question with rate laws][1]][1] Now the rate law for the reaction (i.e reaction rate) can be written as: $$ R= k[N_2O_5] $$ my main question is, WHAT is this reaction equal to? what I mean here is, whether $$k[N_2O_5]= -d[N_2O_5]/dt$$ or is it $$k[N_2O_5]= -1/2 \frac{d}{dt} [N_2O_5] $$ ? The latter seems to be more apt, as the reaction rate must be -1/2 (disappearance rate of N2O5), which adheres to the stoichiometry of the...
View full post »

Thread 'Prove that evolution is constant (Provide at least two arguments to support your position)'

I don't get how to argue it. i can prove: evolution is the ability to adapt, whether it's progression or regression from some point of view, so if evolution is not constant then animal generations couldn`t stay alive for a big amount of time because when climate is changing this generations die. but they dont. so evolution is constant. but its not an argument, right? how to fing arguments when i only prove it.. analytically, i guess it called that (this is indirectly related to biology, im...
View full post »

Similar threads

Biology Water Potential and Osmosis Potatoes Investigation
Replies
6
Views
4K
Concentrating Calcium Bicarbonate Solution
Replies
4
Views
3K
Electrodialysis with different anions
Replies
1
Views
1K
What is the role of hydroxylapatite in the formose reaction and abiogenesis?
Replies
13
Views
2K
What might cell membranes look like on Titan?
Replies
39
Views
9K
Please explain this suggested solution for the field inside a charged hollow sphere
Replies
17
Views
1K
A General solution to Laplacian in cylindrical coordinates
Replies
13
Views
1K
Understand pH Meter Functioning: An Electric Potential Difference
Replies
8
Views
3K
I The potential on the rim of a uniformly charged disk
Replies
4
Views
1K
I How can concentration gradient field come into existence immediately?
Replies
1
Views
3K

Hot Threads

Recent Insights

Back
Top