x

The fluid mosaic membrane

The fluid mosaic membrane

Annotated cross section of a cell surface membrane showing phospholipid bilayer, proteins, cholesterol and carbohydrate chains A cell surface membrane is about 7 nm thick and follows the fluid mosaic model. It is a phospholipid bilayer, with hydrophilic phosphate heads facing watery surroundings and hydrophobic fatty acid tails pointing inward.

Cell membranes and transport Lesson

  1. A Level
  2. /Biology
  3. /Cell membranes and transport

Step-by-step lessons covering Edexcel A A Level Biology Cell membranes and transport for A Level Biology. Each lesson works through exam-style questions in Paper 1, Paper 2 and Paper 3 format. Build a strong foundation in cell biology and biochemistry early on, since later topics on genetics, ecology and physiology all draw on these core concepts.

Lessons

Gas exchange and diffusionCell membranes and transportDNA, RNA and protein synthesisProteins, enzymes and enzyme kineticsDNA replication, mutation and cystic fibrosisMonohybrid inheritance and genetic screening