BIO 327 Lecture Notes - Lecture 3: Metabolic Pathway, Exergonic Reaction, Osmoregulation

• School: Syracuse University
• Department: Biology
• Course: BIO 327
• Professor: Erdman

Document Summary

Plasma membrane exhibits selective permeability: phospholipid bilayer amphipathic because it has both a hydrophilic and hydrophobic region. Membranes are held together by hydrophobic interactions lipids and proteins can shift laterally. Membranes" fluidity depends on temperature: as temp decreases the phospholipids settle and solidify, membrane remains fluid if it is rich in phospholipids and has unsaturated hydrocarbon tails. Unsaturated hydrocarbon tails have kinks (where double bonds are) and cannot pack together as closely as saturated hydrocarbons: fish that live in extreme cold have membranes with high proportion of unsaturated hydrocarbon tails. Membranes must be fluid to work properly fluidity affects permeability and ability of proteins to move to where they are needed most. Single cell may have membrane proteins that carry out various different functions (transport, enzymatic activity, attaching to other cells/ecm). But also a single protein can carry out many functions. Hence the terms fluid structural mosaic and functional mosaic.