Over the Years, the Fluid Mosaic Model Has Been Refined

Multiple Choice

Over the years, the fluid mosaic model has been refined based on recent experimental findings. In the years since the proposal of the fluid mosaic model of the cell membrane, which of the following observations has been added to the model?

A) The membrane is only fluid across a very narrow temperature range.
B) Proteins rarely move in the membrane.
C) Unsaturated lipids are excluded from the membranes and do not contribute to membrane fluidity.
D) The concentration of protein molecules appears to be much higher.
E) Membrane proteins are made of only acidic amino acids.