Which of the following increases membrane fluidity - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
Home
USMLE Articles
USMLE News
USMLE Polls
USMLE Books
USMLE Apps
Go Back   USMLE Forums > USMLE Step 1 Forum

USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 08-02-2010
USMLE Forums Guru
 
Steps History: ---
Posts: 487
Threads: 69
Thanked 296 Times in 133 Posts
Reputation: 316
Question Which of the following increases membrane fluidity

Which of the following increases membrane fluidity under normal conditions?
A. Restriction of rotational movement of proteins and lipids in the membrane
B. Binding of integral membrane proteins with cytoskeletal elements
C. Transbilayer movement of phospholipids in the plasma membrane
D. High cholesterol content of the plasma membrane
E. Binding of an antibody to a cell surface receptor
Reply With Quote Quick reply to this message



  #2  
Old 08-03-2010
USMLE Forums Guru
 
Steps History: ---
Posts: 487
Threads: 69
Thanked 296 Times in 133 Posts
Reputation: 316
Default

no one to answer...!!!
Reply With Quote Quick reply to this message
  #3  
Old 08-03-2010
axax's Avatar
USMLE Forums Addict
 
Steps History: 1+CK+CS
Posts: 115
Threads: 3
Thanked 267 Times in 41 Posts
Reputation: 277
Default

D. High cholesterol content of the plasma membrane
Reply With Quote Quick reply to this message
 
  #4  
Old 08-03-2010
USMLE Forums Scout
 
Steps History: Not yet
Posts: 15
Threads: 3
Thanked 1 Time in 1 Post
Reputation: 11
Default

Quote:
Originally Posted by khushboo View Post
Which of the following increases membrane fluidity under normal conditions?
A. Restriction of rotational movement of proteins and lipids in the membrane
B. Binding of integral membrane proteins with cytoskeletal elements
C. Transbilayer movement of phospholipids in the plasma membrane
D. High cholesterol content of the plasma membrane
E. Binding of an antibody to a cell surface receptor
i think it shud be D.
Reply With Quote Quick reply to this message
  #5  
Old 08-03-2010
USMLE Forums Addict
 
Steps History: Not yet
Posts: 161
Threads: 60
Thanked 23 Times in 19 Posts
Reputation: 33
Send a message via Skype™ to Androide89
Default

E? because the inflammation caused by the Ab
Reply With Quote Quick reply to this message
  #6  
Old 08-03-2010
USMLE Forums Guru
 
Steps History: ---
Posts: 487
Threads: 69
Thanked 296 Times in 133 Posts
Reputation: 316
Default

ya its E...
explanation given by UWORLD....

Binding of an antibody to a cell surface receptor results in lateral diffusion of protein in the lipid bilayer, resulting in patching and capping. When such a divalent or multivalent ligand binds to membrane receptors present as intrinsic membrane proteins, initially there is a homogeneous pattern to the binding. Subsequently, the ligand-receptor complexes undergo patching and eventually capping on the cell surface. Rotational and lateral movements of both proteins and lipids contribute to membrane fluidity. Restriction reduces membrane fluidity. Phospholipids are capable of lateral diffusion, rapid rotation around their long axis, and flexion of their hydrocarbon (fatty acyl) tails. They undergo transbilayer movement, known as "flip-flop," between bilayers in the endoplasmic reticulum; however, this is a very rare occurrence in the plasma membrane. Other factors reduce membrane fluidity. Cholesterol at high concentrations decreases membrane fluidity by interacting with the hydrophobic regions near the polar head groups and stiffening this region of the membrane. Association or binding of integral membrane proteins with cytoskeletal elements on the interior of the cell and peripheral membrane proteins on the extracellular surface limit membrane mobility and fluidity.


can anyone pls explain this in a simpler way!!!
Reply With Quote Quick reply to this message



Reply

Tags
Cell-Biology-, Physiology-, Step-1-Questions

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
Where you live. Leave blank if you don't want to tell.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
nervous system increases the force of muscle contraction Seetal USMLE Step 1 Forum 4 04-16-2010 03:40 PM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)