Chapter 5 Study Guide

6 Pages
Unlock Document

Biological Sciences
Mark Fitzpatrick

Chapter 5: The Dynamic Cell Membrane 5.1 What is the Structure of a Biological Membrane? N Fluid Mosaic Model - a lipid pool, in which proteins and carbohydrates float N The lipids establish the physical integrity of the membrane and create an effective barrier to the rapid passage of hydrophilic materials N The proteins have functions, namely: moving materialsthrough the membrane and receiving chemical signals from the cells external environment N Carbohydrates are crucial for cell recognition of molecules Lipids N Main: phospholipid - has both hydrophilic and hydrophobic regions N Cholesterol isimportant for membrane integrity as it determines fluidity of the fatty acids in the membrane N The fatty acids of the phospholipids make the hydrophobic interior of the membrane somewhat fluid N Lateral movement is always happening; but rarely is there any flipping of phosphoplipids N The inner and outer halves of the bilayer may be quite different in the kinds of phospholipids they contain N Shorter-chain fatty acids, unsaturated fatty acids, and less cholesterol = more fluidity N Fluidity decreases at reduced temperatures; membrane functions may decline in organisms that cannot keep their bodies warm Proteins N Asymmetrically distributed N Proteins have both hydrophilic (have hydrophilic side chains - arginine, histidine, lysine, aspartic acid, glutamic acid, serine, threonine, asparagine, glutamine, tyrosine) and both hydrophobic (alanine, isoleucine, leucine, methionine, phenylalanine, tryptophan, valine) regions N Freeze fracturing - reveals proteins embedded in the bilayer o Freeze o Tissue is fractured via diamondglass knife N Two types of proteins; bond non-covalently o Integral - span the length of the membrane with extrusions o Peripheral - not embedded in the bilayer; polar interacting with polar regions of the membrane N Some proteins are covalently attached to fatty acids - resulting in a special type of proteins N Transmembrane proteins - integral proteins that have hydrophillic extrusions on both sides
More Less

Related notes for BIOA01H3

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.