Nature of science:
Using models as representations of the real world—there are alternative models of membrane structure. (1.11) Falsification of theories with one theory being superseded by another—evidence falsified the Davson-Danielli model. (1.9)
Understandings:
Phospholipids form bilayers in water due to the amphipathic properties of phospholipid molecules.
Membrane proteins are diverse in terms of structure, position in the membrane and function.
Cholesterol is a component of animal cell membranes.
Applications and skills:
Application: Cholesterol in mammalian membranes reduces membrane fluidity and permeability to some solutes.
Skill: Drawing of the fluid mosaic model.
Skill: Analysis of evidence from electron microscopy that led to the proposal of the Davson-Danielli model.
Skill: Analysis of the falsification of the Davson-Danielli model that led to the Singer-Nicolson model.