Limited time offer 20% OFF StudySoup Subscription details

UCONN - PNB 2264 - Class Notes - Week 4

Created by: emj16104 Elite Notetaker

> > > > UCONN - PNB 2264 - Class Notes - Week 4

UCONN - PNB 2264 - Class Notes - Week 4

This preview shows pages 1 - 2 of a 3 page document. to view the rest of the content
background image Week 4- Excitable Cells Membranes -membranes are semipermeable -ion channels and carriers permit movement of ions across the membrane (change 
concentration gradient)
-the uneven distribution of electrical charge(ions) across the membrane creates 
membrane potential 
- the potential energy stored in the membrane is used to send/ receive signals 
inside the cell 
Membrane Potential (V m ) -membrane potential or voltage is the electric potential inside the cell relative to 
the electric potential outside the cell
-net charge inside and outside is zero =no membrane potential  Key Contributions to Vm + set resting potential(close to 
equilibrium potential)
-cells create Vm through ion concentration gradients, concentration gradients are 
created and maintained by a selective membrane and active transport 
-membranes are unequally permeable to various ions (e.g. more permeable to K+ 
than Na+ at rest)
Examples: - with nonselective channel- everything moves down concentration gradient with no
membrane potential
-with selective(+) channel- positive ions move down concentration gradient, 
electrical potential pushes positive ions back bc like repeals like (ions want away 
from increasingly positive membrane and back to the increasingly negative 
membrane) creating a difference in charge 
Vm Balancing Act: -Two opposing forces – concentration gradient and electrical potential  -electrical potential – like repeals like and opposites attract 
background image Equilibrium potential (Ex) - what if situation for a specific ion  -is the membrane potential at which concentration gradient and electrical potential 
forces are equal and opposite
-If ion doesn’t have a concentration gradient the equilibrium potential is zero Misconception -Despite Movement of Ions, Relative Concentrations of Ions DO NOT CHANGE  -Movement only effect space near membrane not whole cell (adding blue food 
coloring to the ocean)
-Small Movements Produce Big Changes in Vm The Nernst Equation  -used to calculate membrane potential if the cell is permeable to a single ion  -equilibrium potential for an ion is determined by charge and concentration 
gradient 
K+            EP -75mV Na+         EP +58mV Cl-           EP -59mV E(Na)                          
+58mV
E(Cl)                           
-59mV
E(K)                            
-75mV

This is the end of the preview. Please to view the rest of the content
Join more than 18,000+ college students at University of Connecticut who use StudySoup to get ahead
School: University of Connecticut
Department: Physiology
Course: Human Physiology and Anatomy
Professor: Kristen Kimball
Term: Fall 2018
Tags:
Name: PNB 2264
Description: Notes cover all power-point information as well as what was covered in class.
Uploaded: 09/25/2018
3 Pages 50 Views 40 Unlocks
  • Better Grades Guarantee
  • 24/7 Homework help
  • Notes, Study Guides, Flashcards + More!
Join StudySoup for FREE
Get Full Access to UCONN - Class Notes - Week 4
Join with Email
Already have an account? Login here
×
Log in to StudySoup
Get Full Access to UCONN - Class Notes - Week 4

Forgot password? Reset password here

Forgot password? Reset your password here

I don't want to reset my password

Need help? Contact support

Need an Account? Is not associated with an account
Sign up
We're here to help

Having trouble accessing your account? Let us help you, contact support at +1(510) 944-1054 or support@studysoup.com

Got it, thanks!
Password Reset Request Sent An email has been sent to the email address associated to your account. Follow the link in the email to reset your password. If you're having trouble finding our email please check your spam folder
Got it, thanks!
Already have an Account? Is already in use
Log in
Incorrect Password The password used to log in with this account is incorrect
Try Again

Forgot password? Reset it here