Quiz 3: Chapter 5 – Membranes and Transport
5.1 An overview of the structure of membranes
- Fluid mosaic model: membrane has fluid lipid bilayer in which proteins are
embedded and float freely.
- Membranes are asymmetrical. The membrane proteins found on 1 ½ of the
bilayer are different in structure and function to the 2 half.
5.2 The Lipid Fabric of a Membrane
- Lipid bilayer: structural frame of membrane. It is also a barrier to water-
- Basic part of membrane: fluid phospholipid bilayer- polar phospholipid
molecules at the surface whereas nonpolar tails together in the interior.
- Organisms have the ability to adjust the fatty acid composition of membrane
lipids to maintain proper fluidity.
5.3 Membrane Proteins
- Proteins in the phospholipid bilayer carry out important functions such as
transport of selected hydrophilic substances, enzymatic activity, recognition,
and signal reception.
- Integral membrane proteins are embedded deeply in the bilayer and