Calculating number of ion channels in lipid bilayer

  • Thread starter af86
  • Start date
  • Tags
    Ion
In summary, using the above information, the number of channels present in a lipid bilayer is 1.27E-17.
  • #1
af86
10
0

Homework Statement



Calculate number of channels present in a lipid bilayer


q = 1.6^-19; D (diffusion constant) = 1.2E-9; C (Concentration); 4.36; k = 1.38E-23; T=298; d = 2.5E-9

Therefore G1 = 1.27E-17

Channel area = 7.07E-18

measured conductance (from injecting Na+ concentration of 100mM) = 149.24uS

Homework Equations



G1 (conductance) = q^2DC/kTd

Gm = g/[tex]\pi[/tex]r^2


The Attempt at a Solution



Conductance of a single channel = 1.27E-12 x 7.07E-18
Number of channels = Gm/G1 ??

Calculating the number of channels is what is getting to me. I have the area of the channel, and I have a measured conductance from injecting a concentration

Thanks!
 
Physics news on Phys.org
  • #2
The conductances sum as you mention. I would think that N = Gm/G1 just as you suppose. Did you not get the right answer?
 
  • #3
Yep. Tried that and my answer came out a few order of magnitudes out...double and triple checked all my work and still..could be that the answer given is incorrect.
Thanks!
 
  • #4
Not sure and without access to my books/notes, may be unable to help here: in your modelling, do you assume that a leak conductance is present?
 
  • #5
Thanks denverdoc.

I figured it out (I think). But yes, leak conductance was taken into account; I think the only way to go is to divide Gm/G1.

Cheers
 
  • #6
Your welcome for what is is was worth--amazing how much one forgets--once upon a time,many moons ago, I was a post doc in an electrophysiology lab.:blushing:
 
  • #7
So I thought I figured this out - but I haven't!

I have some values, as a test, and I can't seem to get it right.

Can anybody please help!? I know it uses the equations above, but something is going wrong in the last step when I'm trying to calculate the number of channels and conductance...I know what the answers should be; number of channels is 3E6


Data:

bilayer area = 1.1E-6m2
bilayer thickness = 2.5E-9m
channel radius = 1.5E-9m
channel thickness = 2.5E-9
diffusion constant = 1.2E-9
dielectric constant = 2.3
change in energy (i.e [tex]\Delta[/tex]U or sometimes [tex]\Delta[/tex]E)

can anybody help please?
 

Related to Calculating number of ion channels in lipid bilayer

1. How do you calculate the number of ion channels in a lipid bilayer?

To calculate the number of ion channels in a lipid bilayer, you will need to know the surface area of the bilayer and the average area occupied by one ion channel. This can be determined using various techniques such as patch-clamp electrophysiology or imaging methods. Once you have these values, simply divide the surface area by the area of one ion channel to get the total number of ion channels in the bilayer.

2. What factors affect the number of ion channels in a lipid bilayer?

The number of ion channels in a lipid bilayer can be influenced by various factors such as the type and concentration of ions present, the composition and fluidity of the bilayer, and the presence of other molecules such as proteins or lipids that may interact with the ion channels. These factors can alter the number, activity, and localization of ion channels in the bilayer.

3. Can the number of ion channels in a lipid bilayer change over time?

Yes, the number of ion channels in a lipid bilayer can change over time. This can be due to various physiological processes such as channel trafficking, insertion or removal of channels from the membrane, or changes in the lipid composition of the bilayer. Additionally, external factors such as temperature, pH, and signaling molecules can also affect the number of ion channels in the bilayer.

4. Are there any mathematical models for predicting the number of ion channels in a lipid bilayer?

Yes, there are various mathematical models and simulations that can be used to predict the number of ion channels in a lipid bilayer. These models take into account factors such as channel density, channel activity, and bilayer properties to estimate the number of channels present. However, experimental validation is necessary to confirm the accuracy of these predictions.

5. Why is it important to know the number of ion channels in a lipid bilayer?

Understanding the number of ion channels in a lipid bilayer is crucial for studying their function and regulation. It can also provide valuable insights into the overall membrane properties and its role in cellular processes such as signal transduction and ion homeostasis. Additionally, knowing the number of ion channels can aid in the development of new drugs and therapeutic strategies targeting these channels.

Similar threads

Ion Flow Through a Channel: Current and Charge
    • Introductory Physics Homework Help
Replies
2
Views
2K
Calculate the number of sodium ions entering an non-myelinated axon
    • Introductory Physics Homework Help
Replies
7
Views
6K
Plasma Creation Method and Ignition of Self-sustained Reaction in Toroidal Reactors
    • Nuclear Engineering
Replies
4
Views
3K
Can Graviton Mass Be Calculated Using Universal Constants?
    • Other Physics Topics
Replies
11
Views
4K

Hot Threads

Recent Insights

Back
Top