-
Benjamin Frankiln "the harmonious human multitude"
When Franklin visited England he conducted an experiment in which he added a small amount of oil to the water in a small pond in Clapham Common.
-He observed that the oil spread in a thin film over the surface of the water until it was "smooth as a looking glass."
-This means that the oil was not dissolved into the water it simply layed on top. -
Lord Raleigh Professer of Natural Science
Lord Raleigh was a physicist whose contributions were great among those was the Fluid Mosiac model.
He felt the matter of the oil spreading on a water surface to be “of great interest". This led him to get accurate measurements of the area to which a known volume of oil would expand. He also calculated the thickness of the oil film. -
Agnes Pockels
Agnes Pockels was a German woman who was conducting experiments in her kitchen.
In a rectangular tray filled to the brim with water, she used a simple balance to determine the force required to detactch a small wooden disk from the surface of the water. She soon found that adding oil or alchol on one side of the partition changed the surface tension.
Agnes Pockels invented a device that measured the exact area of an oil film. -
Charles Earnest Overton
While working on a doctoral degree in Zurich, Charles discovered important properties about the cell membrane contributing greatly to the fluid mosiac model.
Charles concluded chemical nature of a substance determined whether or not the substance could pass through the membrane. Before this discovery it was believed that the membrane was impermeable (doesn't allow for substances to pass) to almost anything but water. -
Irving Langmuir
Irving further researched the nature of oil films, more specifically the lipids and the interaction of oil films with water.
His contributions also included publishing a paper molecular monolayers, Irving also proposed that fatty acid molecules form the monolayer. -
E Gorter and F. Grendel
Concluded that the plasma membrane turns out to be a lipid bilayer made of phospholipids with hydrophillic heads and hydrophobic tails.
They found that the cell membrane is not simply a lipid bilayer but also contains protien and carbohydrate molecules. -
James Danielli and Hugh Davson
Proposed the Davson-Danielli model which suiggested that the protien existed as globular molecules attatched to the sides of the lipid bilayer. The middle was basically a sandwhich of lipids covered on both sides with protiens. -
George E Palade
George studied cell structure and organelles including mitochondria, chloroplasts, the Golgi apparatus, and many others.
Most important to his discovery was that ribosomes are actually parts of the endoplasmic reticulum contrary to primary belief that it was part of mitochondria. He discovered ribosomes have a high ribonucleic acid (RNA) content. and his main discovery was ribosomes. -
J. D Robertson
Robertson made a modified version of the membrane model, based on electron microscope studies, the "unit membrane" . Under the unit membrane model we see the protien layers and the lipid bilayer. -
Jonathan Singer and Garth Nicolson
S. Jonathan Singer and Garth Nicolson proposed a new model, the fluid-mosaic model. In addition, they showed that the proteins move on the membrane like a fluid.
This was demonstrated by an experiment where cells from humans and mice were fused to form single cells later on, the proteins were distributed evenly over the whole membrane.
It has since been found that almost all cells have fluid membranes as proposed by the fluid-mosaic model
