SL Content Statements

• B2.1.1

  Lipid bilayers as the basis of cell membranes

• 
  

  Phospholipids and other amphipathic lipids naturally form continuous sheet-like bilayers in water.

• B2.1.2

  Lipid bilayers as barriers

• 
  

  Students should understand that the hydrophobic hydrocarbon chains that form the core of a membrane have low permeability to large molecules and hydrophilic particles, including ions and polar molecules, so membranes function as effective barriers between aqueous solutions.

• B2.1.4

  Integral and peripheral proteins in membranes

• 
  

  Emphasise that membrane proteins have diverse structures, locations and functions. Integral proteins are embedded in one or both of the lipid layers of a membrane. Peripheral proteins are attached to one or other surface of the bilayer.

• B2.1.9

  Structure and function of glycoproteins and glycolipids

• 
  

  Limit to carbohydrate structures linked to proteins or lipids in membranes, location of carbohydrates on the extracellular side of the membranes, and roles in cell adhesion and cell recognition.

• B2.1.10

  Fluid mosaic model of membrane structure

• 
  

  Students should be able to draw a two-dimensional representation of the model and include peripheral and integral proteins, glycoproteins, phospholipids and cholesterol. Indicate hydrophobic and hydrophilic regions.
  

• B1.1.12

  Formation of phospholipid bilayers as a consequence of the hydrophobic and hydrophilic regions

• 
  

  Students should use and understand the term “amphipathic”.